Susa, Libya: Radical Islamists have killed three Libyan policemen in a raid on their checkpoint near a coastal town east of second city Benghazi, police and medical officials said on Wednesday.

“The three men died from gunshot wounds to the head and chest,” a medical official told AFP on condition of anonymity, adding that a fourth was in critical condition.

Residents said the four men had been stationed at a checkpoint at the western gate of Susa, which lies in the Green Mountains, about 260km east of Benghazi.

They were attacked overnight while performing their duties, residents and a police officer said, pinning responsibility on hard line Islamists.

“Preliminary investigations suggest that extremists were behind these acts,” said Nasser Zayed, who heads the police force of the Green Mountains district. He condemned the targeting of security personnel.

A massive funeral procession for the three men cut across the town in the wake of afternoon prayers.

The incident marks the latest in a string of attacks focused on the army and police forces, which the government has been trying to empower after mass rallies against militias made up of former rebels.

On Friday, demonstrators lobbed hand grenades at security forces and trashed cars after a rally in support of a hard line Salafist group that was evicted from the city last month.

Two members of the newly created National Mobile Forces were wounded on Monday when their car was hit by a grenade during a patrol in south Benghazi, the Lana news agency reported.

The extremist group Ansar Al Sharia and members of Raf Allah Sahati, an Islamist brigade that came under attack from protesters in Benghazi despite its links to the defence ministry, blame security forces for their downfall.

Ansar Al Sharia has been accused of but denied involvement in a September 11-12 assault on the US consulate in the city which killed Ambassador Chris Stevens and three other Americans.

Under pressure at home and abroad to tackle insecurity, Libyan authorities have sought to disband armed formations which have failed to register with the ministries of defence and interior.

They have also moved to place professional army officers at the head of government-sanctioned brigades comprising former rebels who fought to oust Muammar Gaddafi last year.