U.S. drone missiles fired upon Pakistan’s lawless tribal region of North Waziristan have reportedly killed at least seven militants, local officials told Agence France Presse (AFP).

The attack in the Datta Khel area was in response to deadly Taliban suicide bombing which killed 80 people at a Pakistani paramilitary police training center, as revenge for last week’s death of Osama bin Laden.

The Taliban has promised more violence to avenge the killing of bin Laden.

Ehsanullah Ehsan, a spokesman for the Pakistan Taliban, said: This was the first revenge for Osama's martyrdom. Wait for bigger attacks in Pakistan and Afghanistan.

North Waziristan is believed to be filled with Taliban and al-Qaeda members and has long been targeted by U.S. missile strikes.

US forces have now conducted at least three drone strikes on the Afghan-Pak border since bin Laden’s assassination.

On May 6, another drone strike killed at least 12 people in North Waziristan. On May 10, a similar strike killed four people in South Waziristan.

Drone strikes are highly controversial in Pakistan, since many such attacks have killed hundreds of innocent civilians.

Pakistan, which is now under immense pressure to explain why bin Laden was living undetected and undisturbed for years within its borders, has reportedly lost 30,000 lives since Sept. 11, 2001.