A US drone attack has left at least thirteen people dead and five injured in Pakistan's northwestern tribal region amid growing discontent over the increasing number of civilian casualties.

According to local security officials, the attack took place in east of Miranshah in North Waziristan on Saturday.

US drones have targeted the region several times over the past two days.

The raids, initiated by former US President George W. Bush, have been escalated under President Barack Obama. Washington claims the airstrikes target militants.

However, the attacks, operated by CIA in cooperation with the Pentagon, reportedly have killed hundreds of civilians in Pakistan since 2008

The issue of civilian casualties has strained relations between Islamabad and Washington.

Islamabad has repeatedly condemned the strikes, saying they violate the country's sovereignty.

JR/CS/MMN