Tunisian forces launched a land and air operation against Islamist militants near the Algerian border on Friday, the military said, as Tunis battles a crisis sparked by a political slaying.

"A huge operation, with ground and air units, was launched at dawn to clean up the (Chaambi) mountain" area, armed forces spokesman Taoufik Rahmouni told Tunisian media.

Amina Sboui, a Tunisian activist with the topless protest group Femen, was released from jail on Thursday pending her trial for desecrating a cemetery.

Sboui, 18, left the women's prison in Sousse, south of Tunis, where she has been held since May 19, and her supporters issued a photo of her making a victory sign after she was freed.

Algeria's army has reinforced its forces along the eastern border with Tunisia, Interior Minister Daho Ould Kablia said on Thursday, days after the killing of eight Tunisian soldiers.

The soldiers were found on Monday with their throats cut after being ambushed by jihadist militants in Mount Chaambi, an area near the border with Algeria.

Tunisia's leaders started talks on Thursday with opposition and civil society representatives to try to defuse the country's latest political crisis, prompted by last week's murder of an opposition MP.

The talks come as supporters and critics of the government continue to hold street protests every night after breaking the Ramadan fast, particularly in Bardo Square outside parliament.

A roadside bomb went off as a national guard patrol passed south of Tunis early on Wednesday without causing any casualties or damage, a commander said.

The remote-controlled bomb struck at 12:45 am (23:45 GMT Tuesday) near Mhamdia, 30 kilometers (20 miles) from the capital, the town's guard commander Mohamed Jouhri told Shems-FM radio.

Eight Tunisian soldiers were killed Monday in a firefight with "terrorists" near the Algerian border where the army has been tracking al-Qaida-linked militants for months, national television said.

"Eight soldiers were killed as they exchanged fire with a terrorist group in Mount Chaambi," state broadcaster Wataniya 1 said, while other Tunisian media outlets put the toll at between seven and nine.

Tunisian Prime Minister Ali Larayedh Monday called a general election for December 17 after an emergency meeting aimed at easing political tensions and as protests demanded the Islamist government's ouster.

"This government will stay in office: we are not clinging to power, but we have a duty and a responsibility that we will exercise to the end," he told state television, proposing December 17 as the date for a general election.

Tunisian police fired tear gas on Monday to disperse stone-throwing protesters in Sidi Bouzid demanding the resignation of the Islamist-led government, an Agence France Prese correspondent reported.

The demonstrators gathered outside the governor's office in the center-west city, cradle of the 2011 Arab Spring uprising that toppled the regime of dictator Zine El Abidine Ben Ali and home town of an anti-Islamist MP assassinated last week.

Police fired tear gas Sunday at protesters as opponents and supporters of Tunisia's Islamist-led government clashed outside parliament after the burial of the second opposition figure slain this year.

Mohamed Brahmi's cold-blooded murder on Thursday outside his home has stoked tensions in the North African nation where the Arab Spring began.

Thousands of Tunisians took to the streets Saturday for the funeral of an opposition leader assassinated with the same weapon that killed a colleague, as tensions soared after anti-government protests.

After the funeral youths demanding "the fall of the government today!" marched to the National Assembly and hurled rocks and other projectiles at anti-riot police who responded with tear gas.