More than 100 people have died in about a month of unrest that preceded and followed Ben Ali's ouster, the United Nations said.
Meanwhile, hundreds of protesters led a peaceful, if noisy, rally in central Tunis, demanding that former allies of Ben Ali stop clinging to power. The new march was less tense then those of recent days, when police fired tear gas and clubbed protesters.
A caretaker government run by Ben Ali's longtime prime minister has been struggling to calm tensions since Friday. Mohammed Ghannouchi kept his post and is trying to convince Tunisians a new era has arrived — even if the composition of the interim government has many faces from the old guard.
An opposition party that was holding off on joining the new government said it was now definitively pulling out and called for a new Cabinet line-up. "We have decided to pull out and not take part in the government," said Khalil Zaouia, a member of the Democratic Forum for Labor and Liberty (FDLT). "We are calling for new negotiations for the formation of a new government."
Tunisia's official TAP news agency reported that the prosecutor's office moved to investigate overseas bank accounts, real estate and other assets held by Ben Ali, his wife Leila Trabelsi and other relatives.
The country's central bank, meanwhile, took over a bank controlled by a son-in-law of Ben Ali. Zitouna, Tunisia's first Islamic bank, was set up last May by Mohamed Sakher El-Materi, who was named in an investigation opened Wednesday into the domestic and foreign assets held by Ben Ali's family.
El-Materi, a senator, holds a 51 percent stake in the bank and many other assets. He fled following Ben Ali's ouster.
The Swiss president said that her country's federal council agreed to freeze any assets in Switzerland belonging to Ben Ali, to help work up a possible criminal case over alleged stolen funds.
In Geneva, the United Nations' human rights chief, Navi Pillay, said she was sending an "assessment team" to Tunisia in coming days, and estimated more than 100 deaths have occurred so far during the unrest in Tunisia.
Life is yet to return to normal in the country. Tunis' stock exchange, many shops, schools and universities are still closed and some workers have gone on strike. A curfew remains in place.
In an effort to ease tensions, the government moved ahead with plans to release 1,800 prisoners who had less than six months to serve, TAP reported. It was not immediately clear what prompted the release, or whether any were political prisoners.
Tunisia's interim government was expected to hold its first Cabinet meeting Wednesday afternoon.
At the Tunis protest, demonstrators sang nationalist songs and held up signs with "RCD Out!" — referring to Ben Ali's former ruling party — as they rallied on central Avenue Bourguiba. White-and-blue police vans lined the route.
"We want the old government out — and we want them away from anything that has to do with the government," said Hafed El-Maki, 50, who works at the country's largest insurance company. He said he and colleagues staged a strike and overthrew their manager Tuesday.
He said he would not wait for the 60-day time limit for new presidential elections "because that is enough time for the old cronies to set their roots in and start their old ways again, thieving and taking our resources. No way that's happening again."
Opposition figures and the prime minister's office have said that the 60-day time limit accorded in the constitution is unrealistically short, and the delay will more likely be six to seven months.
