Tunis, Jan 23 (Agencies): Thousands of anti-government protesters rallied outside Tunisian Prime Minister Mohammed Ghannouchi's offices on Sunday, calling for him to quit after the downfall of the north African state's 23-year regime.

"The people have come to bring down the government," around 5,000 protesters chanted as they brandished pictures of some of the dozens of people killed by security forces during the uprising against president Zine El Abidine Ben Ali.

They broke through security cordons to reach the doors of the building.

The new transitional government, put in place following Ben Ali's ouster on January 14, has unveiled unprecedented freedoms but is still led by Ghannouchi. Other old regime figures have also held on to key posts.

"We have come to bring down the rest of the dictatorship," said Mohammed Layani, an elderly man draped in a Tunisian flag, who arrived with hundreds of others from the region in central Tunisia where the uprising began.

The protest was supported by the General Union of Tunisian Workers, known under its French acronym as UGTT, which played a key role in anti-Ben Ali protests and has refused to recognise the fledgling government.

The state news agency, meanwhile, said security forces had detained two more figures linked to the old regime: Senate head Abdallah Kallel, who was a former interior minister, and Abdel Aziz Ben Dhia, a key adviser to Ben Ali and key ideologue of the old regime.

They are being held under house arrest, the report said.

Thousands took part in peaceful anti-government demonstration in Tunis on Saturday and were joined by hundreds of police officers, some of whom briefly blocked a car carrying the country's interim president Foued Mebazaa.

Public assemblies of more than three people are officially banned under a state of emergency that remains in place, along with a night-time curfew.

The curfew has been eased and schools and universities, which have been shut since January 10, are expected to begin re-opening this week.

Ghannouchi has been prime minister in Tunisia since 1999 and has promised to quit politics after the north African state's first democratic elections since independence from France in 1956.

Mebazaa has promised a "total break" with Ben Ali's 23-year rule and the government has announced that political prisoners will be released, media censorship lifted and all political parties legalised.