Relatives of Pakistanis killed in U.S. unmanned drone attacks have filed a complaint with the police, seeking the arrest of a retired CIA official they say approved the strikes.

At a press conference Monday in Islamabad, their lawyer Shahzad Akbar said he was trying to get an international arrest warrant for John Rizzo, who was general counsel to the CIA until 2009.

The complaint said one of Rizzo's responsibilities was to “approve a list of persons to be killed every month in Pakistan” by unmanned drones.

Drone strikes have targeted a large number of militants, including al-Qaida and Taliban figures. But human rights groups say many civilians have also fallen victim to these attacks, which have been concentrated in the tribal area of Waziristan on the Afghan border.

The United States does not publicly acknowledge the strikes, which Pakistan has criticized as violating its sovereignty. But the CIA and the U.S. military are the only forces deploying the unmanned aircraft in the region. U.S. officials say the missile strikes have severely weakened al-Qaida's leadership.

After U.S. special forces killed al-Qaida chief Osama bin Laden in a secret raid in May, Pakistan demanded an end to drone operations. But the U.S. has largely ignored the demand.