The attack on the 10-acre Badaber base outside Peshawar on Friday is the largest assault on military personnel this year, and the highest profile in Peshawar since the school massacre last year when terrorists killed 145, mostly children.

About seven to 10 militants launched the base attack early Friday morning. Security forces responded, killing six, Army spokesman Maj. Gen. Asim Bajwa said in a series of tweets.

Soldiers were combing through the facility looking for the others.

The military side suffered two injuries, including an Army major who was shot in the thigh, Bajwa said.

The Pakistani Taliban, known in the country as Tehrik-i-Taliban, claimed responsibility for the attack in a statement.

Badaber Air Base was built by the United States in the 1950s and was used as a listening post to intercept radio information from the Soviet Union.