A strike by an unmanned US drone aircraft has killed 15 people near the Afghan border, Pakistani officials say.

Two missiles are reported to have hit a suspected militant compound before dawn in Hesokhel, to the east of Miranshah, the capital of North Waziristan.

Pakistan's foreign ministry strongly condemned the strike, calling it "illegal", Reuters news agency reports.

The frontier tribal region is considered a hub of activity by al-Qaeda and Taliban militants.

There have been eight US drone strikes in the past two weeks despite Pakistani demands for them to be stopped.

In the latest incident, the first missile struck the compound in Hesokhel before dawn, killing three militants, security officials said.

A second missile then killed 12 more militants who had arrived at the scene, they added.

The bodies of the suspected militants have not yet been identified, but there were unconfirmed reports that foreigners were among the dead.

Analysis US President Barack Obama personally approves every single drone strike against suspected terrorists, so he can take full moral responsibility for the deaths these cause. That is the main thrust of a long, detailed and fascinating piece in the New York Times. It comes as Experts have been telling me that the president is wrong to see drones as a "silver bullet" that solves some critical problems about the morality and efficacy of America's use of military power.

It is the eighth and deadliest attack since 23 March, marking a considerable upsurge in the use of the controversial US drone programme, reports the BBC's Aleem Maqbool in Islamabad.

It has come about since a deal to reopen Nato supply routes through Pakistan fell through.

The Pakistani government closed the routes six months ago in protest at a US air strike along the Afghan border in which 24 Pakistani soldiers were killed, an episode which contributed to the current crisis in relations between Washington and Islamabad, our correspondent adds.

Pakistan says the drone attacks fuel anti-US sentiment and claim civilian casualties along with militants. The US insists the strikes are effective.

The strike comes days after more details of the Obama administration's drone policy emerged in the US.

Administration officials told the New York Times that Mr Obama and top security officials regularly consult on adding militants to a drone "kill list" - and said the US president personally approves or vetoes each strike.