Afghan officials say a top commander of the Islamic State (IS) extremist group has been killed in a suspected U.S. drone strike in eastern Afghanistan.

A spokesman for the Nangarhar provincial governor said Mullah Bozorg, a leader of the IS group in Afghanistan, was killed along with seven fighters late on November 18.

The spokesman, Attaullah Khugyani, said the strike was carried out in the Lagharjo area of Kot district.

He added that weapons, ammunition, and explosives belonging to the group were also seized and destroyed.

"A commander of Daesh was killed in Kot district of Nangarhar Province," the Afghan Defense Ministry confirmed in a statement on November 19, using the Arabic acronym for the group.

IS militants have been active in Nangarhar, where they have seized pockets of territory in the past two years.

The group has recently spread to the neighboring provinces of Kunar and Zabul, located along the porous border with Pakistan.

The extremist group has also claimed responsibility for deadly attacks in Kabul, the most recent a November 16 attack that killed six people near the Defense Ministry building.

In October, the IS group claimed responsibility for two separate attacks on Shi'ite worshippers in Kabul and the northern city of Mazar-e Sharif that killed dozens of people.

The United States has stepped up air strikes against IS militants and rival Al-Qaeda fighters in the past year.

The top U.S. military commander in Afghanistan, Army General John Nicholson, said in September that there are up to 1,300 IS militants in the country who receive money, guidance, and communications support from IS leaders in Syria and Iraq.

He said most IS fighters were former members of the Pakistani Taliban, an Al-Qaeda-linked militant group fighting against Islamabad.

With reporting by dpa and Khaama