ISLAMABAD, Pakistan  Two missiles fired from a remotely piloted American aircraft struck a militant base on Tuesday in the South Waziristan tribal region, killing 16 militants, according to intelligence officials and residents reached by telephone.

A recent attack on the same village, Zangara, missed the leader of the Pakistani Taliban by hours, a Pakistani security official said soon after that missile strike.

The United States and Pakistan routinely withhold comment on suspected drone attacks.

The Pakistani military, which is locked in renewed battle with the Taliban, has been preparing a full-scale offensive in South Waziristan, where the leader of the Pakistani Taliban, Baitullah Mehsud, is based. In the prelude to the offensive, drone attacks have appeared to try to home in on Mr. Mehsud and forces loyal to him.

Before that, the United States was sending drones mainly to attack foreign members of Al Qaeda or Taliban commanders who focused their attacks on neighboring Afghanistan. Mr. Mehsud, however, has taken on the Pakistani government and is accused of masterminding a string of deadly suicide bombings in the country.