Tunisia’s ruling Islamists and the opposition met Saturday to discuss a new constitution on the second day of hard-won negotiations to resolve a months-old political crisis.

Tunisia's ruling Islamists and the opposition met Saturday to discuss a new constitution on the second day of hard-won negotiations to resolve a months-old political crisis.

The murder in July of an opposition leader, Mohammed Brahmi, by suspected extremists triggered growing calls for the resignation of the government led by the moderate Islamist party Ennahda.

On Friday, Prime Minister Ali Larayedh made a written pledge to resign and pave the way for a cabinet of independents headed by a new premier who is to be named within a week.

A first meeting of the much-delayed national dialogue opened on Friday afternoon and the divided factions met behind closed doors into the early hours of Saturday.

The UGTT trade union mediating the negotiations said the talks focused on appointing a committee that will be tasked with forming the new cabinet.

Saturday's session was to focus on forming a commission of experts to
finalize a proposed constitution, a task which has dragged on for two years and that now must be completed within a month.

Meanwhile, the National Constituent Assembly (NCA) was also scheduled to convene after 60 opposition lawmakers ended a boycott of the body they started after Brahmi's assassination.

NCA President Mustapha Ben Jaafar was also due to address the assembly later in the day.

A commission tasked with selecting candidates to form an independent elections body was also due to meet on Saturday.

The roadmap to end the political crisis, brokered by the UGTT, set a deadline of one week for the formation of the body that will organize elections.

But despite the beginning of talks on Friday after three months of stalemate, many were still wary of Ennahda's intentions.

Opposition MP Selma Mabrouk wrote on Facebook: "Vigilance will be the  rule for all those who want this process to succeed, because we are clearly not safe from Ennahda's usual attempts to barter."

Although local press voiced some relief that talks were finally underway, newspapers also urged caution.

"The national dialogue is not easy at all. Political parties will have to come to agree on in three weeks what they have not managed to form in two years," daily Le Quotidien said.

La Presse asked if the negotiators were "really committed to working out this last-chance national dialogue".

The talks also come amid a tense security situation in Tunisia, after six
policemen were killed in a clash with suspected militants in the central Sidi Bouzid region on Wednesday.

Tensions were compounded as the 40,000-member police union threatened the government with demonstrations if it did not work to guarantee the safety of police officers faced with the "terrorist threat".

In a statement released late Friday, The National Union of Interior Security Forces also demanded the resignation within 48 hours of senior security officials it said had been appointed "on the basis of their allegiance' to Ennahda.

Since the uprising that ousted Zine El Abidine Ben Ali's regime, the country has been rocked by violence blamed on militant groups suppressed under the veteran strongman.

Public anger has been mounting over the death toll from extremist violence, which saw two Ennahda offices torched on Thursday as seven slain police officers were laid to rest.

The government has admitted it has struggled to contain the militants but blamed a lack of resources.