A US drone fired two missiles at a suspected militant compound in northwest Pakistan on Wednesday, killing three people, security officials said.

One missile hit a house in the Tappi area about 20 kilometres (12 miles) east of Miranshah, the main town in North Waziristan tribal district which is a stronghold of Taliban and Al-Qaeda-linked militants.

The other hit a vehicle parked outside, they said.

One security official in the northwestern city of Peshawar said the target was a militant compound and those killed were insurgents.

"It was a militant compound being used to store arms and ammunition," he said, requesting anonymity.

"Three militants were killed. The casualties were not high because there not many militants inside."

Locals said three cows, apparently meant for sacrifice on the Muslim festival of Eid-al-Adha being celebrated in the tribal region on Friday, were also killed in the attack.

Wednesday's strike was the third by unmanned US aircraft in the Miranshah area this month. On October 11, 18 insurgents, most reportedly Afghans, were killed in a drone strike in the nearby tribal region of Orakzai in the deadliest attack in more than a year.

The covert US attacks are unpopular in Pakistan, where the government slams them as a violation of sovereignty, but American officials believe they are a vital weapon against Islamist militants.

Earlier this month, cricket legend turned politician Imran Khan led thousands of supporters in a motorcade from the capital Islamabad to the edge of the tribal belt to protest against the US strikes.