Twelve militants were killed in air attacks by Pakistani security forces in a tribal region, while 16 soldiers went missing and were feared to have been abducted by militants.

Military spokesman Major-General Waheed Arshad said helicopters intercepted militants in Degan area of North Waziristan tribal region following attack on an army convoy.

He said five soldiers were injured in an improvised explosive device attack. The ultras fled after the attack and the army called helicopters in aid to target the attackers, he said.

Arshad said the militants tried to escape in two trucks and the trucks were also destroyed in the attack. Twelve militants were reportedly killed, he said.

He also said that a group of 16 soldiers had gone missing on Thursday and the search operation has been started to trace them.

Arshad said they were coming from Spinkai area in South Wazristan to Jandola, another town in the region, but did not reach till the evening, their scheduled arrival time.

"When they did not report at their arrival place, they were registered as missing," he said.

In another incident, unidentified masked men shot dead two pro-government tribesmen in the troubled North Waziristan tribal region, witnesses said.

They said the tribesmen were against the suspected militants hiding in the region. The assailants fled after the attack in Mir Ali, a major town in the region.

The tribesmen were near a market when masked gunmen sprayed bullets at them, killing them on the spot.

Target killings were stopped after the local militants signed an agreement with the government in North Waziristan in September 2006.