The beheading of a young shepherd by jihadists has aroused anger and frustration in Tunisia's Sidi Bouzid where extremist violence has compounded the woes of an impoverished region.

Mabrouk Soltani, 16, was murdered as his sheep grazed on Mount Mghilla.

U.S. Secretary of State John Kerry arrived in Tunis on Friday to take part in a strategic dialogue aimed at bolstering political and economic ties with the North African nation.

Kerry will be meeting members of the National Dialogue Quartet, who last month won the Nobel Peace Prize for their role in promoting a democratic transition after the Arab Spring revolution of 2011.

Rival ambitions, insults and accusations of violence have brought Tunisia's ruling party to the brink of collapse as the country struggles to lead the way towards a post-Arab Spring democracy.

The secularist Nidaa Tounes party was already weakened by the departure of its leader Beji Caid Essebsi, in line with the constitution after he was elected president last December.

A Tunisian street vendor who set himself on fire after authorities seized his merchandise has died, a health official said on Monday.

"The young man was admitted to hospital with third degree burns on Friday. He died of his injuries today," said Imed Maaloul, head of health services in Tunisia's second city Sfax.

Tunisian civil society groups won the Nobel Peace Prize on Friday for helping to create the only democracy to emerge from the Arab Spring, at a time when the country is under threat from jihadist violence.

The Nobel panel said the award to the National Dialogue Quartet was intended as an "encouragement to the Tunisian people" and as an inspiration for others, particularly in the turbulent Middle East.

A lawmaker with Tunisia's main, anti-Islamist political party said he escaped an assassination bid while driving to work Thursday in the coastal city of Sousse.

The popular resort city was the site in June of a beachfront massacre in which a jihadist gunman killed 38 foreign tourists.

Human Rights Watch called on the Tunisian authorities on Monday to free a 22-year-old student jailed last week for homosexuality and to repeal the law that criminalizes consensual sodomy.

"The Tunisian government should not be prosecuting people for private and consensual sexual acts," said HRW's deputy Middle East and North Africa director Eric Goldstein.

A Tunisian court has sentenced a student to a year behind bars on charges of homosexuality, in a judgment condemned by local rights groups, his lawyer said Thursday. 

The youth had been detained on September 6 in the Mediterranean resort area of Sousse for questioning in connection with a murder after his telephone number was found on the victim, lawyer Fadoua Braham said.

Tunisian opposition parties and independent figures have called for a demonstration Saturday against a controversial anti-corruption bill, defying a ban on public protests under a state of emergency.

The protest on Tunis's Habib Bourguiba Avenue, a focal point of the country's 2011 revolution, will "demand a withdrawal of the bill which creates impunity and divides Tunisia," said al-Joumhouri party secretary general Maya Jribi.

A Tunisian border guard was killed in a shootout with jihadists on the border with Algeria, officials said Monday, in an attack claimed by the North African country's main extremist group.

Finance Minister Slim Chaker said one guard was killed and three others wounded when they were "attacked close to the Bouchebka border post" late Sunday.