Libya’s deputy industry minister has been shot dead during a visit to his hometown of Sirte, east of the capital Tripoli.

Local media quoted officials as saying unknown gunmen “sprayed bullets” at Hassan al-Droui near a central market.

It is the first assassination of a member of Libya’s transitional government.

Libya has suffered continuing lawlessness since the overthrow of Col Muammar Gaddafi in October 2011.

The motive behind Mr al-Droui’s assassination is unclear.

Most killings of this kind, which are common in eastern cities like Benghazi and Derna, usually target military and police figures and are often blamed on extreme Islamists groups operating there, says the BBC’s Rana Jawad in Tripoli.

Mr al-Droui was a former member of the National Transitional Council, the political arm of the 2011 uprising.

He was appointed to his role by the transitional government's first prime minister and kept his position when Ali Zeidan took over.

Sirte was the site of the final battle of Libya’s civil war, during which Col Gaddafi was captured and shot dead while trying to hide from rebels.

Libya has been struggling to assert itself over up to 1,700 different armed militias, each with their own goals, following Col Gaddafi’s death.

At least 19 people were killed in clashes between rival tribes in the southern city of Sabha on Saturday.

The fighting was reportedly sparked by the killing of a bodyguard protecting the city’s militia leader, a member of the Awlad Suleiman tribe.

Fellow tribesmen accused the rival Toubou of murdering the leader.

The violence is the worst between the tribes since they struck a ceasefire agreement in March 2012.

Members of the Toubou minority tribe live mainly in neighbouring Chad, but are also found in southern Libya, Niger and Sudan.

They have in the past complained of not being treated as equals by Arabs from the coastal cities of the north, who tend to dominate the country’s government and security forces.

Southern Libya thrives on the business of smuggling contraband goods as well as human trafficking, our correspondent says.

Many of the clashes between tribes there are rooted in competition over smuggling routes.

•Text courtesy of BBC. Photo shows late Libyan deputy minister Hassan al-Droui.