CNN  — 

At least four people were killed when missiles thought to be from a U.S. drone struck a militant compound in tribal North Waziristan on Sunday, Pakistani military sources told CNN.

Two missiles hit a compound in the village of Data Khel, the sources said.

The officials asked not to be named because they were not authorized to speak to the media.

North Waziristan is one of seven districts of Pakistan and borders Afghanistan.

The U.S. routinely does not comment on suspected drone strikes.