Police said on Friday that Qari Shahid Usman was captured on Thursday with four other militants.

Ali Raza, a Pakistani police official, said ten kilograms of explosives were also seized in the raid.

Another police official, speaking on condition of anonymity, said Usman was the Karachi city chief of al-Qaeda’s South Asia wing set up in September by the militant group’s leader, Ayman al-Zawahiri.

Usman received militant training in Afghanistan, the official said.

Authorities had previously accused Usman’s al-Qaeda branch of a September attack at the naval facility in Karachi.

Al-Qaeda-linked militants have been in charge of numerous attacks against Pakistani security forces and civilians, and managed to spread their influence in various regions of the country despite sporadic offensives by the Pakistani army.

On December 6, a key al-Qaeda leader, Adnan Gulshair el-Shukrijumah, was killed by the Pakistan forces.

Since 2004, Pakistan has been fighting against extremist groups in the northwest and its semi-autonomous tribal belt after its army entered the tribal region to capture al-Qaeda militants infiltrating from Afghanistan.

Thousands of Pakistanis have lost their lives in bombings and other militant attacks since 2001, when Islamabad entered an alliance with Washington in the so-called war on terror.