KABUL, Afghanistan — The leader of ISIS in Afghanistan was killed in an airstrike on Saturday along with 10 other fighters, officials said.

U.S. forces conducted a counter-terrorism strike in Nangarhar province targeting a senior leader of a terrorist group, said a spokesperson for Operation Resolute Support, a NATO-led mission which trains and advises Afghan forces.

Spokesman Lt. Colonel Martin L. O’Donnell referred NBC News to a statement from Afghan leader Ashraf Ghani’s deputy spokesperson which confirmed that Abu Sayeed Orakzai, Islamic State's leader in Afghanistan, had been killed.

The provincial governor of Nangarhar said Orakzai was the fourth ISIS leader in Afghanistan to be killed since July 2017.

The group has developed a stronghold in the province, on Afghanistan's porous eastern border with Pakistan, and become one of the country’s most dangerous militant groups.

The local affiliate of ISIS, sometimes known as Islamic State Khorasan (ISIS-K) after an old name for the region that includes Afghanistan, has been active since 2015, fighting the Taliban as well as Afghan and U.S. forces.

O'Donnell of Operation Resolute Support said the U.S. "unrelentingly" continues its counter-terrorism efforts against ISIS, Al-Qaeda, and other regional and international terrorist groups.

"These efforts target the real enemies of Afghanistan, the same enemies who threaten America," he said.

Earlier this week, Ghani called for a temporary cease-fire to coincide with the Muslim holiday Eid al-Adha. The Taliban responded to the request by holding 21 people hostage after seizing them from three buses in the north of the country on Monday.

Ghani has been trying to nudge the resurgent Taliban, which has been fighting to overthrow the U.S.-backed government in Kabul since 2001, into peace talks. The Taliban has not officially responded to Ghani's offer.

Meanwhile, the exact number of ISIS fighters in Afghanistan is difficult to calculate because the fighters frequently switch allegiances. But the U.S. military estimates that there are about 2,000.

Earlier this month, ISIS claimed responsibility for an attack on a university preparatory academy in Kabul which killed 48 and injured 67 others. The school was in a neighborhood popular with minority Hazara, who are Shiite Muslim and considered apostates by the terror group.

Prior to the attack, 150 ISIS fighters surrendered to Afghan security forces in the northwestern province of Jawzjan, where the group is fighting for control of smuggling routes into neighboring Turkmenistan.

Ahmed Mengli reported from Kabul, and Saphora Smith from London.