Drone strikes hitting three compounds in Pakistan have killed at least 18 on Friday. The strikes come after repeated demands from Pakistan that the use of drones on its territory must stop, the latest demand just one day ago.

Agencies report that Friday's are the seventh drone strike in Pakisan's North Waziristan area this week.

On Thursday, Pakistan's Foreign Ministry said in a statement:  "A senior U.S. diplomat was called to the Ministry of Foreign Affairs and informed that the drone strikes were unlawful, against international law and a violation of Pakistan's sovereignty. It was emphatically stated that such attacks were unacceptable."

As New York Times reports, demands that the U.S. stop its drone campaign on Pakistan have been ongoing. "It was the eighth time in 12 months that the Pakistani government had issued a formal protest on the issue, a senior Pakistani official said. "