Tunisia will set up buffer zones in the south of the country, along the borders with Libya and Algeria, to fight against "terrorism," Defense Minister Rachid Sabbagh said Thursday.

"Setting up these zones is necessary because of the current situation and to fight against the threats that hang over Tunisia," including "terrorism and arms trafficking," Sabbagh said.

Islamist premier Ali Larayedh on Tuesday accused Tunisia's main Salafist movement of liaising with al-Qaida and carrying out "terrorist" attacks that have rocked the country since the 2011 revolution, including two political assassinations.

Ansar al-Sharia "is responsible for the assassinations of (Chokri) Belaid and (Mohammed) Brahmi, as well as our martyrs in the police and the national army," Larayedh told a news conference, referring to the two politicians killed in separate attacks in February and July.

Thousands of protesters marched in Tunis Saturday, on the first day of a planned week-long campaign aimed at bringing down the Islamist-led government, amid political deadlock in the north country.

They headed in the direction of the national assembly, where activists and opposition MPs have gathered regularly since the July 25 assassination of secular politician Mohammed Brahmi, demanding the departure of the government led by the Islamist party Ennahda.

Tunisia's opposition Friday rejected the ruling Islamists' proposals for ending a month-long political crisis, ahead of anti-government protests, saying their offer to enter talks on a technocrat administration was insufficient.

"All negotiations without the (immediate) dissolution of the government are a waste of time," said Taieb Baccouche, a representative of the National Salvation Front (NSF), the broad coalition of opposition parties.

Tunisia's ruling Islamist party indicated Thursday it was ready to negotiate with the opposition on the formation of an apolitical government, in order to end a month-long political crisis.

The announcement of what would be a key concession that Ennahda has until now resisted came after its leader, Rachid Ghannouchi, met Houcine Abassi, the secretary general of the powerful UGTT union, which has been mediating between the rival factions.

Tunisia's powerful UGTT trade union confederation resumed mediation efforts on Wednesday to try to end weeks of deadlock between the ruling Islamist Ennahda party and the mainly secular opposition.

The talks, which again showed no sign of progress, come amid turmoil and bloodshed in nearby Egypt, following the army's ouster of Islamist president Mohamed Morsi last month, and with anti-government protests planned across Tunisia this weekend.

A Tunisian rights group on Wednesday called for the release of Ridha Grira, the last defense minister of ousted dictator Zine El Abidine Ben Ali, who is suffering from cancer.

Detained since September 2011, Grira is being prosecuted for his part in a number of corruption cases linked to the Ben Ali regime, which was overthrown in a popular uprising in 2011.

Tunisia's powerful UGTT labor union on Wednesday resumed mediation between the ruling Islamist party and the opposition in a bid to end the political crisis plaguing the country.

The talks come amid political turmoil and bloodshed in nearby Egypt, following the army's ouster of Islamist president Mohammed Morsi last month, and with anti-government protests planned across Tunisia this weekend.

Bloodbath in Egypt, civil war in Syria, stalemate in Tunisia: the Arab Spring has stoked turmoil because of a lack of maturity among the region's new political class, analysts say.

When popular uprisings swept away long-standing dictators in Egypt, Libya and Tunisia in 2011, hopes were running high for a smooth transition and a fresh start.

Tunisia's prime minister warned Tuesday that he would not tolerate any attacks on state institutions during planned protests to call for his Islamist-led government's resignation, state media reported.

"Ali Larayedh said there would be no hesitation or restraint faced with those who by terrorism, anarchy or rebellion carried out attacks on institutions of the state," the official TAP news agency said.