The Taliban have killed the leader of the Islamic State cell responsible for the suicide bombing at the international airport in Kabul, Afghanistan, in August 2021 that killed 13 US troops and as many as 170 civilians, the White House said on Tuesday.

Four senior American officials said that US intelligence analysts became aware in early April that the mastermind of the attack, whom they declined to identify, had died in a Taliban operation in Afghanistan.

It was unclear whether the Taliban were specifically targeting the insurgent or he was killed in one of the increasing numbers of attacks between Taliban and Islamic State fighters, the officials said.

John F. Kirby, a spokesman for the National Security Council, called the Taliban operation “another in a series of high-profile leadership losses” that the Islamic State cell, known as Islamic State Khorasan province, or ISIS-K, had suffered this year.

The officials said that based on classified intelligence reports analysts concluded with “high confidence” that the chief plotter of the airport attack had been killed. But the officials offered no evidence to support that conclusion or other details about his purported death.