PESHAWAR, PAKISTAN - Pakistani security forces said Thursday that troops had killed more than 50 militants while ground and air forces battled against Islamist insurgents in parts of the northwest.

Government troops are locked in battles against armed groups in parts of Pakistan's northwest and the lawless tribal belt on the Afghan border where US officials have said Al-Qaeda and Taliban-linked insurgents enjoy safe havens.

"At least 28 militants of Lashkar-e-Islam were killed in shelling by helicopter gunships," Major Fazal Khan, a spokesman for the paramilitary Frontier Corps unit, told AFP.

He said the operation was conducted overnight in the Tirah valley of Khyber, one of Pakistan's seven semi-autonomous tribal areas and through which flows the bulk of supplies destined for US-led and NATO troops in Afghanistan.

Death tolls released by Pakistan are impossible to confirm independently because fighting takes place in closed military zones and the army has faced scepticism that more than 1,600 militants have been killed since late April.

Lashkar-e-Islam said eight of its members died.

"Eight of our members were killed. We don't know about the rest, they might be civilians," Mistri Gul, a spokesman for the group, told AFP.

In June 2008, Pakistan poured paramilitary troops into Khyber to counter militants threatening to take over the northwest capital Peshawar and to stop attacks on convoys supplying Western troops based in Afghanistan.

Pakistani authorities accuse the radical Lashkar-e-Islam of kidnapping for ransom in Peshawar, running torture centres and private jails.

The group is also accused of attacking convoys ferrying supplies to NATO and US troops in Afghanistan that travel through the historic Khyber Pass.

In the northwest district of Swat, the military said security forces had killed 23 militants, including 17 around Shah Dheri in clashes, during the last 24 hours.

On the outskirts of Peshawar, a remote-controlled bomb ripped through a police patrol on Thursday, killing at least two policemen, said city police chief Safwat Ghayur.

There was no immediate claim of responsibility for the attack.

Many of the recent bombings in northwest Pakistan have been seen as Islamist attempts to avenge the two-month military offensive against the Taliban in Swat and nearby districts that has been welcomed by the United States. --AFP