MIRAMSHAH: At least five militants were killed in two US drone attacks in Pakistan's northwestern tribal region near the Afghan border on Friday, security officials said.

The first drone fired two missiles targeting a suspected militant vehicle in Khaisor town, about 30 kilometres north of Miramshah, the main town in the North Waziristan region, they said.

The attack left three militants dead, one official said. Another security official put the death toll at four.

Two more missiles followed about 15 minutes after the first strike, killing two militants, local officials said.

The second strike came as militants were engaged in rescue work after the first attack, a security official said.

Another official in Peshawar confirmed a total of five militants were killed in the two attacks.

Missile attacks doubled in the tribal areas last year as the campaign was stepped up, with more than 100 drone strikes killing over 670 people in 2010 compared with 45 strikes that killed 420 in 2009, according to an AFP tally.

The last drone hit on Tuesday, when missiles targeting a compound killed five militants near Wana, the main town in South Waziristan tribal region.