Continued violence raises questions about stability as the interim government struggles to stem unrest.

Tunisia has asked military reservists to report for duty in a new drive to restore order, three weeks after an uprising overthrew the north African nation's long-term president.

Tuesday's order came as security officials in the coalition government said there was a conspiracy by officials close to the old administration to spread chaos and take back power.

The interim government was put in place after Zine al-Abidine Ben Ali, the Tunisian president, fled to Saudi Arabia.

After days of gunfights and looting immediately after Ben Ali was pushed out, it had seemed security was being restored but since last week violence has flared again, raising new questions about Tunisia's stability.

Some members of the caretaker government of Mohamed Ghannouchi, the new prime minister, have accused Ben Ali loyalists of fomenting unrest against the new leadership in an attempt to derail the transition to democracy.

The government banned on Sunday the former governing party, the Constitutional Democratic Assembly, and on Monday parliament approved a law granting decree powers to Fouad Mebazaa, the interim president.

The military has for weeks been in the streets helping keep order and filling the gap left by a police force whose ranks have been thinned by desertions and absenteeism.

"The defence ministry has called on retired members of the army, navy and air force ... to go to the regional centres of conscription and mobilisation nearest to their place of residence," said a ministry statement reported by the official TAP news agency.

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.

Missing Police

In a separate statement, the interior ministry urged police to play their role in bringing back security.

Public respect for the police is low because many Tunisians blame them for carrying out acts of violent repression during Ben Ali's rule, and suspect them of trying to undermine the new government after he fled.

"The ministry of interior calls on police officers to guarantee the security of the country and to act to help all those who ask their help in case of danger," the official news agency quoted the ministry as saying.

"In cases where police leave their workplace to answer urgent calls, they must return as soon as the emergency is dealt with.

If they do not return they will be considered as having left their job."

At least five people have been killed in violent incidents in provincial towns since Friday, including two shot dead in the northern city of El Kef when police tried to disperse protesters.

There were no reports of any deaths or injuries on Monday but protesters clashed with police again in El Kef and set fire to buildings in the town, local media reported.

In Tunis, the Tunisian capital, about 300 employees of the foreign ministry staged a protest rally outside their workplace to demand that Ahmed Ounaiss, the minister, steps down.

He had angered many Tunisians by lavishing praise on Michele Alliot-Marie, the French foreign minister, who is under fire at home from opposition politicians who accuse her of having cosy relations with the ousted Ben Ali administration.