TRIPOLI - The Libyan foreign minister on Sunday said in a letter to UN Secretary General Ban Ki-moon that the residents of the city of Sirte are subjected to genocide by Islamic State (IS) affiliates.

The terrorist group is using all kinds of weapons to kill dozens of innocent civilians, said the minister, Mohamed Al-Dairi,  who demanded the United Nations to provide the Libyan army with weapons to combat IS affiliates.

Violent clashes broke out last week in the IS-dominated city, some 500 km east of the capital Tripoli, between the extremist group and local fighters after a key Salafi preacher was assassinated. The violence killed at least 15 people, according to officials and local residents.

"The United Nations Support Mission in Libya (UNSMIL) strongly condemns attacks by the so-called Islamic State (Daesh) in the city of Sirte, including reports of indiscriminate shelling of residential neighborhoods and the killing of captives the terrorist group has controlled since May," the UN agency said in a statement on Saturday.

It stressed that a political agreement between Libya's rival political factions will help confront IS threat.

Libya has been suffering a turmoil since the fall and killing of its former leader Muammar Gaddafi in 2011. The country is plagued with escalating violence and similar attacks. (Xinhua)