Pakistani intelligence officials say two U.S. drone strikes have killed at least 14 militants in the country's northwest.

Both attacks on Thursday took place along the Afghan border in the North Waziristan tribal agency, considered a main stronghold of al-Qaida and Taliban fighters.

The first strike hit a compound in the village of Spalga, killing at least six militants. Hours later, missiles hit a vehicle traveling near the town of Mir Ali, killing at least eight fighters.

Earlier this month, U.S. President Barack Obama publicly acknowledged for the first time that the United States uses drone strikes against militants in Pakistan.

Mr. Obama defended the operations, which have greatly increased during his administration, saying they are used for “very precise, precision strikes” in the fight against al-Qaida.

Pakistan rejects the attacks as a violation of its sovereignty.

The Washington-based New America Foundation says drone strikes in Pakistan have killed between 1,700 and 2,700 people in the past eight years.

Elsewhere in Pakistan's northwest Thursday, officials say a suicide bomber targeting members of an anti-Taliban militia killed at least one person in the Upper Dir tribal region.