WORLD BRIEFING / PAKISTAN

Two missile attacks killed 13 militants in northwestern Pakistan’s tribal belt in the latest apparent strikes in a covert U.S. program that American officials are thinking about intensifying.

Drones have carried out more than 70 missile attacks in the border region over the last year, but Washington rarely acknowledges the strikes.

The U.S. says the mountainous tribal area is a base for militant attacks on American and other NATO troops in neighboring Afghanistan and a stronghold of Al Qaeda’s senior leadership.

One of the latest attacks targeted a Taliban compound in the South Waziristan tribal region. The attack killed six insurgents, including two Uzbek fighters, and wounded six others, two Pakistani intelligence officials said. They spoke on condition of anonymity because they were not authorized to release the information.

The attack occurred in Sararogha village, the base of Pakistani Taliban chief Baitullah Mahsud, who was killed in an Aug. 5 airstrike believed to have been carried out by the United States.

A second missile struck a house owned by a known Afghan militant in North Waziristan, officials said. Seven insurgents died, they said. The officials also spoke on condition of anonymity, citing policy.