KABUL • The head of Islamic State in Afghanistan - believed to be the mastermind behind several high-profile attacks, including an assault on a military hospital that claimed at least 50 lives - has been killed, according to US and Afghan officials.

Abdul Hasib, whose group is affiliated with the Islamic State in Iraq and Syria (ISIS), was killed last month in a targeted raid by special forces in the eastern province of Nangarhar, the presidential palace in Kabul said in a statement.

Information about his death came days after the US dropped its largest non-nuclear bomb on ISIS hideouts in the same area.

Analysts described him as "obscure", but authorities ascribed responsibility to him for high-profile assaults in Kabul, including the savage attack on a military hospital in March, when assailants stabbed bedridden patients and threw grenades into crowded wards.

"This is the second ISIS-K emir we have killed in nine months, along with dozens of their leaders and hundreds of their fighters," Nato commander in Afghanistan, General John Nicholson, said, using the acronym denoting the group's local affiliate, Islamic State Khorasan Province.

The first, Hafiz Saeed, was killed in a US air strike last July. Like Hasib, his death was seen as a setback, but not a mortal blow to the group.

"The death of Abdul Hasib does not make a difference for the Daesh group in Afghanistan," Kabul-based writer and analyst Ahmad Saeedi said, using the Arabic name for ISIS. They will simply put another leader in place, he added.

US Forces-Afghanistan officials claim defections and recent battlefield losses have reduced the local ISIS presence from a peak of as many as 3,000 fighters to a maximum of 800.

AGENCE FRANCE-PRESSE