The leader of a fledgling Islamic State of Iraq and the Levant (ISIL) affiliate in Afghanistan and Pakistan has been killed in a US air strike, days after the deaths of several other senior members of the group, Afghan officials say.

Hafiz Saeed and more than 30 other fighters were killed in Friday's air strike in Nangarhar's Achin District, Abdul Hassib Sediqi, a spokesman for Afghanistan's National Directorate of Security, told the Associated Press news agency.

US officials declined to confirm the deaths.

Afghan officials earlier said an earlier US air strike on Tuesday killed the affiliate's second-highest official, Gul Zaman, and six others, including a former Pakistani Taliban spokesman named Shahidullah Shahid who had defected to become ISIL's third most senior leader.

"With the killings of Hafiz Saeed, Gul Zaman and Shahidullah Shahid, who were the high-profile figures of Daesh [ISIL] in Afghanistan, we have destroyed the base of ISIL," said Sediqi.

Sediqi offered no photographs or other evidence to show the strikes killed the ISIL leaders, though he said Afghan authorities verified a corpse from Friday's strike was Saeed.

NATO officials declined to immediately comment on the claim, saying they would issue a statement later on Saturday.

US Army Colonel Brian Tribus, a spokesman for US Forces-Afghanistan, confirmed Americans carried out an air strike on Friday in Nangarhar's Achin District, bordering Pakistan, but declined to comment further.

ISIL's small but growing push in to Afghanistan has brought the group into conflict with the Taliban, with most members of the Afghan movement refusing to pledge allegiance to ISIL's self-declared caliph, Abu Bakr al-Baghdadi. 

Source: AP