Tunisian security forces fought gun battles with armed men in the capital on Sunday, as politicians tried to form a unity government two days after the president was ousted after more than 23 years in power.
Breaking a relative calm enforced by the army in Tunis earlier in the day, state television reported two separate gun battles, one near the central bank building and another outside an opposition party's headquarters about 1 km (half mile) away.
A military source told Reuters that Tunisian special forces were also exchanging fire with members of the ousted president's security force near the presidential palace in a Tunis surburb.
The firefights suggested a worsening of violence following drive-by shootings and jailbreaks on Saturday in which scores of inmates were killed in the chaos.
State TV and police said people holding Swedish and German passports had been arrested after the latest clashes.
Military and police sources said security forces had killed two gunmen stationed on a rooftop near the central bank, state TV's reporter said from the scene, a block from the Interior Ministry. A military official told the station that the two men had been killed by fire directed from a helicopter.
Earlier, the opposition PDP party said police and military had stopped a carload of armed men and shots were fired outside its headquarters. Police said two of the suspects caught after chasing them into apartment buildings had Swedish passports, and they also arrested a Tunisian.
Police detained four people carrying German passports over the same incident, state TV said, quoting a security source.
The official who was in charge of security for ex-President Zine al-Abidine Ben Ali, who fled the country on Friday after a wave of rioting, is to appear in court on charges of stoking violence and threatening national security. Al Jazeera television said a replacement had been appointed.
On Sunday, tanks were stationed around Tunis and soldiers were guarding public buildings. Residents, some of whom had said they were starting to get back to normal life during daylight hours, rebuilt makeshift barricades from branches and trash cans to block their streets and protect property as the night curfew approached.
"We came out on the streets and dressed in white vests so we can identify one another. We told the police in the neighbourhood that we are here and we're dressed in white - it was during curfew hours some brought sticks and we collected rocks," one man told Reuters Television earlier in the day.
Sunday was not a working day but some people were shopping for food. For the first time in days, a few vans and pick-up trucks were making deliveries.
On the highway heading north into Tunis, a group of youths with sticks and knives were stopping private cars and robbing them just a few kilometres from an army checkpoint, a Reuters Television crew said.
Showing their contempt for Ben Ali's family, several hundred people filed through the empty, ransacked home of the former president's nephew, Kaif Ben Ali, taking photographs, picking up plants as souvenirs and stripping out plumbing fixtures.
The villa is in the chic Mediterranean resort of Hammamet, about 60 km (40 miles) from the capital, where many of the moneyed elite close to the ousted president had their homes.
The speaker of parliament Fouad Mebazza, sworn in as interim president, has asked Prime Minister Mohamed Ghannouchi to form a government of national unity and constitutional authorities said a presidential election should be held within 60 days.