2345 GMT: Al Arabiya reports that President Ben Ali's plane has landed in Jeddah, Saudi Arabia.
2155 GMT: President Obama has issued a statement:
I condemn and deplore the use of violence against citizens peacefully voicing their opinion in Tunisia, and I applaud the courage and dignity of the Tunisian people. The United States stands with the entire international community in bearing witness to this brave and determined struggle for the universal rights that we must all uphold, and we will long remember the images of the Tunisian people seeking to make their voices heard. I urge all parties to maintain calm and avoid violence, and call on the Tunisian government to respect human rights, and to hold free and fair elections in the near future that reflect the true will and aspirations of the Tunisian people.
As I have said before, each nation gives life to the principle of democracy in its own way, grounded in the traditions of its own people, and those countries that respect the universal rights of their people are stronger and more successful than those that do not. I have no doubt that Tunisia's future will be brighter if it is guided by the voices of the Tunisian people.
2115 GMT: French Government sources have made clear that President Nicolas Sarkozy refused to let former President Ben Ali land in France.
2040 GMT: Within an hour of the declaration by former Prime Minister Mohammad Ghannouchi that he was temporary President, rumbles began against his accession. There are claims that the move is unconstitutional, as Speaker of Parliament Fuad Mbazza should have assumed power under the Constitution.
Al Jazeera reports from that city of Kasserine that lawyers are now protesting against Ghannouchi, asking him to respect the law and step down.
2035 GMT: In contrast to the report from Tunisia's Nesma TV (see 2005 GMT), Al Jazeera says Sakher El Materi, the son-in-law of former President Ben Ali, has not been arrested and is heading to Dubai.
2025 GMT: Al Jazeera is now saying that President Ben Ali's plane is heading to a country in the Gulf.
Claims are circulating that Ben Ali's wife Leila Trabelsi is in Dubai.
2005 GMT: Tunisia's Nesma TV reports that Sakher El Materi, the son-in-law of former President Ben Ali, was arrested along with other family members.
Materi, 31, controlled the Porsche and Volkswagen car franchise, the Zeitouna Bank, an insurance firm, and a radio channel.
Last autumn, Materi met the US Ambassador, Gordon Gray. Discussion included commercial relations, especially with the opening of a direct air route between Tunis and New York. Gray spoke of his recent visit to the US to fulfill the wishes of President Obama to increase imports of Tunisian products" and the knowledge of Tunisia shown by corporations such as Boeing and Motorola encouraging them "to invest and settle" in the country. Gray added that small- and medium-size enterprises had expressed interest in the Tunisian market and had begun developing contacts.
Here is Materi's website celebrating his accomplishments.
2000 GMT: France has promised to consult with the new Tunisian Government if former Presidenti Ben Ali seeks political asylum.
1955 GMT: Al Jazeera has been reporting from a protest outside the Tunisian Embassy in Cairo.
1950 GMT: As French officials prepare for the arrival of former President Ben Ali, Al Arabiya speaks to the pilot who refused to transport Ben Ali's family: "They are war criminals. I refused to fly them out."
The pilot added, "There were five family members of Ben Ali on the plane. I cannot tell you who was there but I only know how many."
1900 GMT: Picture of the Day? A crying policeman comforted by protesters:
1805 GMT: And now the report is that ousted President Ben Ali is not going to Malta but to Paris.
1800 GMT: It is the former Prime Minister Mohammed Ghannouchi --- not Speaker of Parliament Fuad Mbazza --- who has formally taken charge.
Ghannouchi has promised to respect the Constitution and restore stability.
1754 GMT: Le Monde reports that teenagers ransacked the homes of President Ben Ali's wife, Leila Trabelsi, and her relatives this afternoon in Gammarth, the chic residential suburb north of Tunis.
The looters took away gas canisters, televisions, and VCRs, while police nearby watched without intervening.
1752 GMT: Al Jazeera says fallen President Ben Ali is heading for Malta.
1744 GMT: The live announcement by the Speaker of Parliament is now taking place.
1740 GMT: Reports say a ruling committee has been formed, headed by the Speaker of Parliament and including the Minister of Defense.
1725 GMT: Counter-Narrative. According to Al Arabiya, Speaker of Parliament Parliament Speaker Fuad Mbazaa says he is running Tunisia temporarily and will announce early elections. Under Tunisian law, those elections must take place within 60 days.
It is unclear whether this has been coordinated with today's military action.
Meanwhile, Al Jazeera reports President Ben Ali has left Tunisia.
1720 GMT: Al Jazeera is now reporting that "head of the regime", i.e., President Ben Ali and not just his family, are trying to leave the country.
"Members of the family" --- but not presumably Ben Ali himself --- have been arrested at the airport.
1715 GMT: Claims in social media that General Habib Ammar will be taking charge of the country. Tunisian state television has said an "important announcement" is imminent.
1700 GMT: A prominent Internet activist passes on this claim from the son of an Army General: the army has demanded President Ben Ali's resignation, and members of his family, including his wife Leila Trabelsi Ben Ali, have been prevented from leaving at the airport.
1655 GMT: Al Jazeera reports that Hamma Hammami, spokesperson of the banned Tunisian Workers Communist Party, has been released from detention.
1645 GMT: AFP reports Tunis Airport and Tunisian airspace are closed.
1635 GMT: Al Jazeera AND Al Arabiya both report heavy gunfire in Tunis, with many injured. Al Jazeera reports tear gas in front of the Ministry of Interior.
The curfew is now from 5 p.m. to 7 a.m.
1625 GMT: A summary of the turn this afternoon, as peaceful protest gave way to conflict....
Wire services report that 8000 people were demonstrating outside the Ministry of Interior, chanting, "Ben Ali, leave!" and "Ben Ali, assassin!", when gunshots rang out and police fired tear gas to disperse them. Crowds of youths who retreated a short distance from the building started throwing stones at the police, who responded by firing more tear gas grenades.
This version differs from an earlier report that the tear gas was fired when protesters got onto the roof of the Ministry (see 1400 GMT).
1545 GMT: I'm back from Manchester --- thanks to Ali Yenidunya for keeping the LiveBlog ticking over --- to find stunning developments. News came through 45 minutes that President Ben Ali had announced he was dismissing the Government and calling elections within six months.
Now I learn that a state of emergency has been declared. State television says security forces can use force to halt a suspect after giving a warning. No more than three people can assemble in a public space.
A curfew will be in place from 6 p.m. today.
1515 GMT: The Tunisian state news agency says President Ben Ali is dismissing the Government and calling elections within six months.
1400 GMT: Associated Press is reporting that police have fired tear gas after protesters climbed onto the roof of the Ministry of Interior.
1325 GMT: Tunisia's Ambassador to UNESCO has resigned and announced his resignation on local radio in Paris
1300 GMT: Hospital sources in and near Tunis say 13 people were killed on Thursday.
1245 GMT: Prominent blogger Slim Amamou, who was detained last week, has been freed.
1224 GMT: The take-away chant from today's demonstration in Tunis: "No to Ben Ali, the Uprising Continues".
1220 GMT: The US and British Governments have advised their citizens to avoid non-essential travel to Tunisia.
1215 GMT: Speaking to Al Arabiya from the protest in front of the Ministry of Interior, Ahmed Chebbi of the opposition Democratic Party claims there are 100,000 demonstrators.
145 GMT: The rally continues peacefully in Tunis. The take-away line so far is the demand of the protesters for the immediate resignation of President Ben Ali.
1045 GMT: Crowd in front of the Ministry of Interior in Tunis:
1010 GMT: Reuters is estimating 5000 protesters in front of the Ministry of Interior.
0910 GMT: A mass rally is now on its way to the Ministry of Interior in Tunis.
0800 GMT: Perhaps the sharpest phrase to capture Thursday's political developments --- if not the drama of the mass rallies that put Tunisia's President in a corner --- came from Brian Whitaker as he watched Ben Ali's speech announcing concessions from reduced prices on bread, milk, and sugar to freedom on the Internet to his retreat from power and elections in 2014:
"If (this) fails, he has only one card left: resignation."
But even this penultimate card was read differently observers. Some celebrated a great victory; others saw no more than a ruse by the President, who has held power since 1987, to maintain authority as he rallied troops to push back against the protests.
The official opposition was welcoming. "This is something we have asked for for a long time, and it is very good that he has promised not to put himself forward for the election," Najib Chebbi, the former leader of the Progressive Democratic Party, said. "The president has touched on the heart of the issue, demands for reform. That is very important and I salute that."
That in turn leads to thoughts of a "unity" government, which Chebbi has requested. This morning the Foreign Minister is telling French radio that this is a possibility.
Other poltical actors are cautious. "The speech opens up possibilities," Mustapha Ben Jaafar, head of the Democratic Forum for Work and Liberties, said, "[But] these intentions still have to be applied."
Rafik Ouerchefani, a supporter of the centre-left Ettajdid party, was sceptical that Ben Ali's promises would be delivered.
"I am happy with the speech, but let's not forget the dead," he said.
Perhaps most importantly, the manoeuvres do not take in the vital aspect of the demonstrations on the streets. Even as Ben Ali declared that he was ordering a halt to live fire, there were reports that protesters had been killed.
And so, while further political statements are made, the noise to notice may be that on the largest boulevards of Tunis: a mass march has been called for 10 a.m. (0900 GMT).