Three opposition ministers quit Tunisia's new coalition government on Tuesday in protest at the presence of members of the party of ousted leader Zine al-Abidine Ben Ali.
Prime Minister Mohamed Ghannouchi brought opposition leaders into the coalition on Monday after the president fled to Saudi Arabia following weeks of violent street protests. But key 'old guard' figures kept their jobs, angering many.
Police in Tunis repeatedly used teargas in an attempt to break up a protest by several hundred opposition party supporters and trade unionists who labelled the new government a "sham". Protesters would scatter, but then regroup to continue.
Abid al-Briki of the Tunisian labour union UGTT said its three ministers would withdraw from the government because it included members of Ben Ali's RCD party.
"This is in response to the demands of people on the streets," Briki said.
The ministers, who were given junior positions in the cabinet, are Houssine Dimassi, nominated for the training and employment portfolio, and two ministers of state, Abdeljelil Bedoui and Anouar Ben Gueddour.
"The new government is a sham. It's an insult to the revolution that claimed lives and blood," said student Ahmed al-Haji.
"The problem with the interim government is it has a number of ministers from the old government," protester Sami bin Hassan said.
Ghannouchi defended his government, saying some ministers had been kept on because they were needed in the run-up to elections, expected in the next two months.
"We have tried to put together a mix that takes into account the different forces in the country to create the conditions to be able to start reforms," Ghannouchi told Europe 1 radio.
Ghannouchi rejected suggestions that the Ben Ali "dictatorship" would continue under a new guise.
His foreign minister, Kamel Morjane, said during a visit to Egypt that the interim government would respond to issues that had angered protesters, such as corruption, and would be preparing for new elections.
"It may be possible that the next government will not have any member of the former government," he said.
Paris-based opposition leader Moncef Marzouki arrived at Tunis airport to be met by 200 cheering supporters.
"The revolution must continue," Marzouki, who went into exile after being harassed by Ben Ali's intelligence services, said.
"Today is a great victory. It is magnificent to be in a free country," said Marzouki, head of the small centre-left Congress for the Republic. "I, who fled, I was a fugitive, I am back in my country."
The weeks of protests against poverty and unemployment in Tunisia which forced Ben Ali from office prompted fears across the Arab world that similarly repressive governments might also face popular unrest.
In Tunis on Tuesday, people in several parts of the city reported hearing sporadic gunfire overnight but there was significantly less gunfire than on previous nights.
A Reuters photographer in the Ariana suburb of Tunis said local people were organising neighbourhood groups to clean up the damage left by several days of lawlessness.
Interior Minister Ahmed Friaa said on Monday that at least 78 people had been killed in the unrest, and the cost so far in damage and lost business was 3 billion dinars ($2 billion).
Ghannouchi promised to release all political prisoners and to investigate those suspected of corruption Those behind the killing of demonstrators would face justice.
"All those who are behind this massacre, this carnage, will be accountable to the justice system."
The wave of protests has hit stock and currency markets from Jordan to Morocco amid fears that the Tunisian unrest would spread abroad.
The prime minister said the ministers of defence, interior, finance and foreign affairs under Ben Ali would keep their jobs in the new government.
Among opposition figures, Najib Chebbi, founder of the Progressive Democratic Party (PDP), was named minister of regional development, Ettajdid party leader Ahmed Ibrahim higher education minister and Mustafa Ben Jaafar, head of the Union of Freedom and Labour, health minister.