Tunisian Prime Minister Mongi Hamdi on Saturday urged Libya to locate two Tunisian journalists who went missing in the neighboring violence-hit country after their arrest by an armed group.

Investigative journalist Sofiene Chourabi and photographer Nadhir Ktari disappeared on September 8 in the eastern Libyan region of Ajdabiya.

A Tunisian jailed for two years for posting caricatures of the Prophet Mohammed online has been set free on a second conviction, his lawyer said on Wednesday.

Jabeur Mejri was freed in March after serving two years of a seven-and-a-half-year term for the caricatures but was jailed again in April for eight months for insulting a court clerk during an argument about the date of a summons.

The first trials of prisoners accused of "terrorism" in Tunisia since the 2011 revolution could open later this month, with 600 defendants facing prosecution, its justice minister said Thursday.

Hafedh Ben Salah told Agence France-Presse in an interview that the defendants included al-Qaida-linked jihadists who have been battling the Tunisian army near the Algerian border for nearly two years.

Campaigning officially got under way Saturday for Tunisian parliamentary elections seen as a milestone in efforts to establish a democratic foothold in the birthplace of the Arab Spring.

Hailed as a rare success story following the uprisings that swept much of the region in 2011, the North African nation hopes the vote will be a highlight of a sometimes troubled transition.

Tunisian youths disillusioned with the post-revolution era have flocked to join jihadists overseas, making the birthplace of the Arab Spring the top source of foreign fighters in Syria.

Twenty-seven candidates including officials who served under former dictator Zine El Abidine Ben Ali have signed up as candidates for Tunisia's November 23 presidential election, the organizing body said Tuesday.

No fewer than 70 people originally filed applications to the Isie, which is organizing the first presidential election since the January 2011 revolt forced Ben Ali to flee.

With the world on high alert over foreign fighters joining jihadist ranks in Syria and Iraq, Balkan states are launching efforts to clamp down on recruiting in their region, considered fertile ground by Islamists.

Of the more than 20 million people in southeast Europe, more than five million are Muslims, and an economic slump in weak states battered by past wars has fired up some of the disenfranchised.

Tunisia's moderate Islamist party Ennahda appealed Monday for U.S. support as the country heads into vital elections, warning democracy remains fragile in the nation that triggered the Arab Spring.

Tunisians ousted longtime dictator Zine El Abidine Ben Ali in January 2011 and Ennahda emerged at the head of the pack in elections nine months later with 37 percent of the vote.

Tunisian President Moncef Marzouki announced Saturday he will stand for re-election in November, in a key vote almost four years after a revolt that sparked the Arab Spring uprisings.

The polls, along with parliamentary elections in October, are seen as the final step in Tunisia's transition after more than two decades under strongman Zine El Abidine Ben Ali who was toppled in 2011.

Tunisian troops killed two suspected foreign militants in an overnight firefight, the government said on Wednesday, after it raised its alert level nationwide in the run-up to a general election.

Prime Minister Mehdi Jomaa, who has warned of a "serious terrorist threat" as the October 26 election nears, asked the army to be ready to intervene in towns and cities as he raised the alert level on Tuesday evening.