Tunisian party leaders were meeting Monday to try to agree on a new premier in a bid to resolve a months-long political crisis linked to rising jihadist violence.

The government led by the moderate Islamist Ennahda party is to be replaced as part of a roadmap aimed at breaking the political stalemate, which included the launch of a "national dialogue" on Friday.

The meeting of 21 party chiefs began at around 1600 GMT Monday, according to the powerful UGTT trade union, which has been mediating talks between the government and the opposition.

The new prime minister will have two weeks to form a government of independents under the timetable for the talks.

Local media have mooted a number of figures who could replace incumbent Prime Minister Ali Larayedh, but until now, no firm candidates have emerged.

The elected Constituent National Assembly has until the end of November to draw up a new constitution, an electoral law and to form a commission to organise polls, and the body met Monday to discuss reforms to speed up the drafting of a new basic law.

The Assembly will meet in plenary on Tuesday morning to discuss the creation of an authority to organise elections. According to the roadmap, this authority must be set up by the end of the week.

Larayedh has pledged to step down so long as the timetable is respected.

"The Assembly must honour its commitments ... we envisage that it will complete its task within three weeks," Ennahda's veteran leader Rached Ghannouchi said on Monday as the talks got under way.

The crisis erupted in July, when the assassination of an opposition leader, Mohammed Brahmi, by suspected jihadists triggered calls for the resignation of the Ennahda-led government.

Tensions ran high in Tunis late Monday as the national dialogue went ahead, and members from rival leftist and Islamist student unions clashed on a university campus, leaving five people wounded.

Rise in jihadist violence

Since the 2011 uprising that ousted Zine El Abidine Ben Ali and kicked off the Arab Spring, Tunisia has suffered a series of attacks blamed on jihadist groups previously suppressed under the long-ruling strongman.

The extremist groups have mounted several attacks on security forces, especially in the rugged border region with Algeria.

The government's inability to decisively end the violence has infuriated the opposition and, more recently, the security forces themselves.

A powerful, 40,000-member police union has threatened demonstrations if the government does not do more to guarantee the safety of police.

Hundreds of protesters gathered Monday outside the interior ministry in Tunis in what was billed as a "symbolic national funeral" for slain members of the security forces.

"Tunisia is free! Terrorism out!" the demonstrators chanted. "With our souls and with our blood, we will avenge the martyrs."

Riadh Rezgui, a spokesman for the police union, has accused the government of "deliberately weakening the security services, given that we don't have the necessary equipment, not even bullet-proof vests."

The interior ministry denounced the union's calls to rally as "unacceptable," adding that they were tantamount to a "threat of rebellion" and urging police and security officers not to heed them.

The same union organised a demonstration earlier this month in which members drove Larayedh and President Moncef Marzouki out of a memorial ceremony for two policemen killed in clashes with militants.

Despite the rising discontent in their ranks, security forces have nevertheless pressed their campaign against militants.

Late Sunday, the interior ministry said eight members of an armed cell had been arrested in connection with the killing of six police officers in clashes last week.

Counterterrorism units arrested "eight terrorist elements implicated in the recent events" in the Sidi Bouzid region in central Tunisia, it said, adding that explosives and arms were also seized.

The violence in Sidi Bouzid -- birthplace of the Arab Spring -- fuelled outrage over the persistent jihadist violence.

Last Thursday protesters torched Ennahda's office in Kef, the town where one of the policemen killed in last week's clashes was to be buried.