US pilotless spy planes on Sunday flew over a Pakistani tribal town bordering Afghanistan just hours after a missile strike killed at least four people, residents said.

Two missiles from suspected US drones overnight struck a compound just outside Miranshah, the main town in the restive North Waziristan district, which is seen as a safe haven for Al-Qaeda and Taliban militants.

The targeted compound was the residence of Taliban militant Omar Daraz, a security official told AFP, giving no further details.

There was no reaction to the attacks from the Pakistan government, though the military said they were aware of the strike.

"We have reports about an explosion incident in Miranshah," chief military spokesman Major General Athar Abbas told AFP.

He said he could not confirm whether the missile attack was launched by US aircraft.

Residents on Sunday said they could see three drones overhead as they sifted through the remains of the destroyed compound searching for further casualties.

Some tribesmen fired at the drones, but there was no damage to the aircraft or any return fire.

Pakistan has been protesting recent missile strikes blamed on US forces based in Afghanistan and has termed them a violation of its sovereignty.

A similar suspected US missile strike on a house in the same district on Thursday killed nine people including six Arab militants, according to security officials.

The US has stepped up attacks on militants in Pakistani territory since a new civilian government came to power in Islamabad in March, stoking anti-US sentiment in Pakistan.

Relations have also been strained by a raid by US special operations forces into Pakistan on September 3 which killed several Pakistanis.