Gunshots were fired in the centre of the Tunisian capital on Tuesday, people in the area said, in a new blow to faltering efforts to restore security after the overthrow of the autocratic president.
Three witnesses told Reuters they heard shooting coming from streets near Avenue Bourguiba, the main thoroughfare in Tunis, but none could see who was responsible.
I heard sporadic gunfire, one of the witnesses, who was near the Tunis city government building, told Reuters. Soon after, the area was back to normal with no signs of any disturbances.
Security had seemed to be slowly returning to Tunisia three weeks after a wave of protests forced President Zine al-Abidine Ben Ali, in power for 23 years, to flee to Saudi Arabia.
But in the past few days violence has flared up again, with at least five people killed since Friday in clashes between police and protesters in provincial towns. Army reservists have been called up to help restore order.
The gunshots on Tuesday were the first time shooting had been heard in the capital for at least two weeks.
Tunisia's uprising against Ben Ali's authoritarian rule inspired protest movements elsewhere in the Arab world, notably in Egypt, and its halting progress towards stability is being watched closely in the region.
The European Union, Tunisia's biggest trading partner and a major donor of development aid, said it was putting together an assistance package at the request of the Tunisian authorities.
In a further show of international support, Britain's foreign minister, William Hague, became the most senior Western official to visit since Ben Ali's ouster.
We are witnessing a moment of opportunity here in Tunisia and in many other countries, an opportunity which should be seized rather than feared, he told a news conference in Tunis.
There were new signs of unrest in provincial towns -- though not on the same scale as on previous days -- with many protesters demanding that regional governors step down because they had ties to Ben Ali's administration.
In the town of Gafsa, near the border with Algeria, a senior school attended by 1,500 pupils caught fire in an apparent arson attack, official media reported.
Two trade union sources in Gassrine, about 250 km (155 miles) southwest of Tunis, told Reuters several hundred people were blocking the highway into the town to protest at what they said was neglect by the central government.
The sources said the governor of the Gassrine region, who was only appointed a few days ago in a purge of regional officials, stepped down on Monday under pressure from protesters who besieged his office.
Protests also forced out the newly-appointed governor of Gafsa region on Tuesday, the official TAP news agency reported.
In a deal meant to defuse the tension, Tunisia's biggest trade union said it had agreed with the government that all governors with ties to the ex-ruling party would be removed.
In Tunis, workers at the foreign ministry were on strike for a second day to demand that the minister, Ahmed Ounaiss, resign. He angered many Tunisians with comments they felt showed he did not fully support Tunisia's change of ruler.
Tunisia is striving to get back to normal as quickly as possible before the turmoil does lasting damage to its economy.
An industry ministry report said the impact on industrial production in January had been limited but it warned: If a few weeks of reduced activity are manageable, a longer period would be dramatic for hundreds of thousands of workers.