A US missile strike targeting a vehicle killed six rebels in a Pakistani tribal region on Friday, local security officials said.

It was the third drone strike in less than last three days that took place close to Miranshah, the main town of the North Waziristan tribal region.

"US drones fired two missiles targeting a rebels' vehicle and killing six militants," a local security official told AFP on condition of anonymity because he was not authorised to speak to media.

Another security official also confirmed the strike and casualties.

He said the identities of those killed were not immediately known.