Islamic State Fighters Take on Libya's Rival Government Forces

Militants claiming allegiance to Islamic State fought forces loyal to Libya's two rival governments in the central city of Sirte and further east in Benghazi, state media and military officials said on Wednesday.

In Sirte, Islamic State militants killed five members of a force loyal to the government that controls Tripoli, a Tripoli-based news agency said. The United Nations and military sources said the attack near a power station on Sirte's outskirts was a suicide bombing.

Fighters loyal to the Tripoli government, sent to Sirte from the western city of Misrata, have clashed with the militants and had set up checkpoints near the power station.

There was also heavy fighting between Islamists and forces loyal to Libya's internationally recognised government, which is based in the east in Benghazi, after Islamic State militants claimed a suicide attack on an army post in the city.

"These suicide attacks show the expanding arm of terrorism that is targeting all sides and that all Libyans stand against," the UN said in a statement.

War planes attacked suspected Islamist positions early on Wednesday, residents and military officials said. Gunfire and rocket propelled grenades could be heard.

Military officials had vowed air attacks on Islamists in response to a suicide bombing on Tuesday which killed seven people in Benghazi. Two more people had been killed by a rocket hitting residential buildings.

Militants claiming ties to Islamic State have exploited the turmoil in Libya, where two governments and parliaments fight for control four years after the ousting of Muammar Gaddafi.

Taking advantage of the security vacuum, just as Islamic State did in Syria and Iraq, the militants expanded recently in Sirte, taking over government offices, universities and a radio station.

The recognised government has been based in the east since a rival faction seized the capital in August and reinstated a previous assembly, challenging the elected parliament which is also based in the east.

Both rely on former rebels who helped oust Gaddafi and now fight each other.

Islamic State militants have claimed several attacks including the storming of a Tripoli hotel and the beheading of 21 Egyptian Copts.

The UN said two brothers of an eastern lawmaker, Abu Bakr Said, had been kidnapped by an armed group in Tripoli. Said is from Tarhouna, a town near Tripoli which was targeted by war planes from the eastern government on Monday. Eight members of a family were killed there, the UN said.