More than 100 people have died in about a month of unrest that preceded and followed Ben Ali's ouster, the U.N. said. Meanwhile, hundreds of protesters led a peaceful - if noisy - rally in central Tunis, demanding that former allies of deposed President Zine El Abidine 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.
Ben Ali fled to Saudi Arabia on Friday after 23 years in power, and a caretaker government run by his longtime prime minister is now struggling to calm tensions. The fragile state of the government highlights Tunisians' questions about who is in control of this moderate Muslim nation on the Mediterranean Sea, popular among European tourists and seen as an ally in the West's fight against terrorism.
Ben Ali's longtime prime minister 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.
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. His relatives - especially his wife's family - were seen as corrupt and dominated many businesses in the nation.
Meanwhile, the Swiss president said Wednesday 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.
While the protesters were fervent - if less combative - on Wednesday, life has yet to return to normal: Tunis' stock exchange, many shops, schools and universities were closed and some workers have gone on strike. A curfew remains in place, thought the government shortened it as security improved.
In another effort to ease tensions, the government moved ahead Wednesday with plans to release 1,800 prisoners who had less than six months to serve, the official state news agency TAP reported. It was not immediately clear what prompted the release, or whether any were political prisoners.
Tunisia's interim government, already hobbled by defections, was expected to hold its first Cabinet meeting Wednesday afternoon.
At the Tunis protest Wednesday, protesters 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 al 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.
Some protesters carried a coffin-like black box with the letters RCD painted in white, and banged the side of the coffin as they walked up and down. Others chanted, or sang.
The unrest has rattled Tunisia's economy, which had seen impressive growth in recent years. Moody's Investor Service downgraded Tunisia's government bond ratings Wednesday, citing "significant uncertainties" surrounding Tunisia's economic and political future.
Moody's cut the rating by one notch, to "Baa3" from "Baa2," and also downgraded its outlook to negative from stable. The new rating is one notch above "junk bond" status.
Labor unions, students and members of the Ennahdha Islamist party - which Ben Ali banned in 1992 and cracked down upon for years - have been among those protesting since his ouster.
A new unity government announced Monday was mostly made up of old guard politicians. A day later, at least four outsider ministers quit, aligning themselves with demonstrators who insist democratic change is impossible with former Ben Ali supporters still in power.