The leader of Tunisia's lower house of parliament is temporarily taking charge of the country after the president fled the nation following weeks of protests.

The prime minister, Mohamed Ghannouchi, said yesterday he was taking over as the temporary ruler because the incumbent, Zine al-Abidine Ben Ali, was temporarily unable to fulfil his duties.

But the Constitutional Council announced that by law the speaker of parliament, not the prime minister, should be the interim president, Tunisian television reported today. The country's new leader will be Fouad Mebazaa.

The constitution requires new presidential elections to be held no later than 60 days from now, Tunisia's highest legal authority on constitutional issues said.

"The Constitutional Council announces that the post of president is definitively vacant so we should refer to article 57 of the constitution, which states that the speaker of parliament occupies the post of president temporarily and calls for elections within a period of between 45 and 60 days," its president, Fathi Abd Ennather, said.

Ben Ali yesterday declared a state of emergency after saying he would dismiss his government and call new elections within six months.

Thousands of angry demonstrators marched through the capital, Tunis, demanding his resignation and he eventually flew out of the country, taking refuge in Saudi Arabia.

Early today rioters burned the main train station in Tunis to the ground. Soldiers intervened to stop looters at a huge supermarket in Ariana, 20 miles north of the capital, as a helicopter hovered. Gunfire could be heard.

Meanwhile in France, the former ruler of the North African country, expatriates celebrated.

About 200 people, some wearing Tunisian flags as capes, huddled together on the Place des Invalides in Paris, after being directed away from the nearby Tunisian embassy.

Haitham Nasri, from Sfax in south Tunisia, was celebrating but warned of further trouble.

"It's like half-time in an important football match, when the home team is up 1-0," said the 21-year-old who has been living in France for two years.

"We're happy with our performance so far but are regrouping for the second half."

Celebrations also spread through the Arab world today, raising hopes that the events in Tunisia could inspire reforms by other authoritative regimes, particularly in Egypt and Jordan.

It's believed there are about 1,000 British expatriates living in Tunisia.

Up to 200 travellers there have registered with the "Locate" page of the Foreign Office website.