TUNIS (Reuters) - Tunisia said it freed the last political prisoners of its fallen strongman on Wednesday as the new caretaker leadership faced more calls for a fuller purge of the old guard from the fledgling national unity coalition. Najib Chebbi, whose move this week from marginalised opposition leader to a ministerial appointment in the new cabinet is emblematic of the new Tunisia, told Reuters: All the political prisoners have been released today. They included members of the banned movement Ennahda. But figures were not available of how many people had been released. Secrecy under veteran former president Zine al-Abidine Ben Ali, who fled to Saudi Arabia, meant that the number of those detained for political reasons was never made public. While authoritarian Arab rulers have long cited the threat of radicals to justify repressive rule to their Western allies, Tunisias opposition has been less visible than those in poorer and less secular states of the region. Hundreds of protesters demonstrated in the Tunisian capital on Wednesday to demand the dismissal of former Ben Ali loyalists from the new government headed by Prime Minister Mohamed Ghannouchi, who was himself premier under the old leadership. He is due to hold a first cabinet meeting on Thursday. Four opposition figures quit the government within a day of being appointed, saying protesters were disappointed at how many old faces were kept on. They feared, they said, that the people were being denied the fruits of their Jasmine Revolution. The weeks of protests over poverty and unemployment, which cost about 100 lives, prompted speculation across the Arab world that other repressive governments might also face unrest. About 500 people protested in Bourguiba Avenue in the centre of Tunis on Wednesday, fewer than in recent days. This will continue every day until we get rid of the ruling party, said Faydi Borni, a teacher. We got rid of the dictator but not the dictatorship. We want rid of this government that shut us up for 30 years. Not all Tunisians back the protests: Weve been living so long under pressure but maybe we should give the government a chance, said one woman bystander, who did not want to give her name. People will have a chance to vote. Around the protest, life continued as normal. Trams were passing through the demonstration. Protesters clapped a woman tram driver who smiled at them as she edged into the crowd. The streets of Tunis were quiet overnight, with no shooting or looting. In a sign security was improving, state television said that the nightly curfew was shortened by three hours. Moncef Marzouki, the leader of a small opposition party who returned to Tunisia from exile in France this week, visited the grave of Mohamed Bouazizi, who set fire to himself in an act of protest and started the wave of unrest which toppled Ben Ali. Marzouki, who plans to run for president, also went to where Bouazizi set himself on fire in the town of Sidi Bouzid. About 300 people greeted him and some lifted him onto their shoulders. People in the crowd carried banners saying: Ghannouchi must go and The people demand that Ben Alis people leave Marzouki called for an independent figure to be appointed in place of the present prime minister to form a government. If the situation continues with a government built on this old dictatorship, the situation will continue on the street and what I want is for Tunisia to return to stability as soon as possible, he told Reuters in an interview. In a bid to stem dissent, Ghannouchi on Tuesday quit Ben Alis old ruling party, the RCD. Opposition leader Chebbi told Reuters on Wednesday that the government would also announce that RCD officials would no longer receive state salaries. Underlining international concern over Tunisia, US President Barack Obama spoke to Egyptian President Hosni Mubarak about Washingtons desire for calm. At a summit in Egypt, the head of the Arab League warned the regions leaders to heed economic and political problems. Switzerland said it was freezing assets of Ben Ali and his entourage. Tunisias state news agency said an investigation would be launched into allegations that Ben Ali, wife Leila, and members of their families had acquired property and stocks abroad. It said there would be an inquiry into the transfer of foreign currency abroad by members of Ben Alis extended family. State television said the government released 1,800 prisoners serving less than six months for minor offences. It was not clear if any of these included any political detainees. France said it had intercepted a shipment of riot gear ordered by Ben Ali just before his downfall last week. The United Nations said it would send a team of human rights officials to Tunisia next week to advise the new coalition government. UN High Commissioner for Human Rights Navi Pillay said she had information that more than 100 people had died in the violence. The Tunisian government puts the figure at 78. Rating agency Moodys Investors Service on Wednesday lowered its credit rating for Tunisia, and Standard and Poors has threatened to do so if uncertainty continues. The cost of insuring Tunisias debt against default rose sharply.