An American spy aircraft fired missiles into restive North Waziristan tribal region on Wednesday and killed at least 17 people, security sources said.


The U.S. drones fired four missiles on a house and a vehicle in the Danda Derpa Khel area of Miranshah, the headquarters of North Waziristan which borders Afghanistan.


Two missiles hit the house while the other two hit the vehicle, residents said.


There was no report about identity of the slain men.


Some unconfirmed reports suggest that suspected militants had been hiding in the house. A senior militant leader was believed to be present at the time of the attack.


The drone attack was the biggest launched this year and the second since Nawaz Sharif took office as prime minister following his victory in the May 11 elections.


The US routinely fired missiles into the Pakistani tribal regions on the plea that the militants use the area for planning attacks across the border into Afghanistan.


Pakistan publicly condemns the strikes. However, the US has refused to halt the CIA-run operations.