The leader of the Islamic State group in Afghanistan was killed by a U.S. drone strike Tuesday, local media report. The attack was first confirmed by Afghanistan’s National Directorate of Security through its Twitter account. At least five other ISIS members were killed in the same strike.

Shahidullah Shahid, the nom de guerre of a former spokesman for the Pakistani Taliban who was sacked by the group after joining ISIS, was believed to be the leader of the militant group’s Khorasan branch. The name refers to a large region that spans historic eastern Persia and today includes parts of Iran, Afghanistan and Pakistan. He is the third top ISIS commander to be killed in Afghanistan this year, according to New York Daily News.

In January, a video allegedly made by Shahid was released showing recent Pakistani and Afghan ISIS recruits beading a Pakistani soldier, imitating the notorious executions by the group and its supporters in the Middle East and Africa. Similar videos have come out of Iraq, Syria, Libya, Yemen and Nigeria.

ISIS has established a growing presence in Afghanistan in recent months as the self-proclaimed Islamic State’s black flag is replacing the Taliban’s white one in the many tribal regions, according to the Independent. Little is known about the group’s size or popularity, and it is unclear whether the Khorasan group is taking orders directly from ISIS commanders in Syria and Iraq or acting independently, Reuters reported earlier this year.

The group began spreading in Afghanistan after a prominent Taliban governor, Mullah Abdul Rauf, a former Guantanamo Bay detainee, pledged allegiance to the Syria and Iraq-based militants and publicly encouraged other Taliban supporters to defect and join ISIS instead. Rauf was killed in a drone strike in February. The group continues to draw many of its new recruits from the Pakistani and Afghan Taliban.

It is yet unclear whether ISIS will respond to the killing of Shahid. The group’s strongest base is in Nangarhar, an eastern province in Afghanistan where supporters have recently been involved in clashes with the Taliban, The Express Tribune reported. The media outlet also said the killing of Shahid confirms speculation that many Pakistani militants have recently crossed into Afghanistan.

Afghanistan has seen rising levels of violence in recent months. A U.N. report published in February found that 2014 was the country's bloodiest year yet since the war began in 2001.