Gunmen assassinate mayor of Libya's biggest port city

Gunmen fatally shot the mayor of Libya's third-largest city, Misrata, late on Sunday, ambushing his car inside the city, security officials said.

The North African oil producer has been in chaos since the 2011 uprising that unseated Muammar Gaddafi, but Misrata, Libya's biggest port, had been relatively peaceful until now.

Gunmen chased the car of Mayor Mohamed Eshtewi after he left Misrata airport following his arrival on a plane from Turkey, a security official said, adding it was unclear who was behind the assassination.

Eshtewi was reported to be returning from a visit to Turkey with other members of the city council.

UN envoy for Libya Ghassan Salame on Twitter denounced the killing and expressed his "profound sadness" over the news.

Britain's ambassador to Libya, Peter Millett, said he was "deeply saddened by (the) senseless murder."

"He worked hard to serve his people," he said on Twitter.

Home to some 400,000 people, Misrata is considered one of Libya's safest cities.

Its powerful militias played a major role in expelling the Islamic State group from the coastal city of Sirte last year.

Misrata, almost 200 kilometres (125 miles) east of Tripoli, is the gateway for food and other imports into Libya and the country's only tax-free zone.

It is one of the few places still frequented by foreign business people fearing poor security elsewhere.