An Afghan military pilot was killed in an attack by unknown armed men in northern Parwan province on Friday, sources said.

Nusrat Koshan, an Afghan Air Force officer, was killed at around 6:30 Friday evening during a skirmish with armed men in the Bagram district of the province, sources added.

Bagram Governor Lala Shirin Raufi told Ariana News that the incident took place in the “Dorahi-e-Qale Khwaja and Qale Narzoy” of in the district.

Raufi said the assailants managed to flee from the area.

No group or individual has claimed responsibility for the attack.

Last week, Reuters reported citing two senior Afghan government officials that at least seven Afghan pilots have been assassinated off base in recent months.

According to Reuters, this series of targeted killings, which haven’t been previously reported, illustrate what U.S. and Afghan officials believe is a deliberate Taliban effort to destroy one of Afghanistan’s most valuable military assets: its corps of U.S.- and NATO-trained military pilots.

In so doing, the Taliban — who have no air force — are looking to level the playing field as they press major ground offensives.

Reuters confirmed the identities of two of the slain pilots through family members but could not independently verify the names of the other five who were allegedly targeted.

In response to questions from Reuters, Taliban spokesman Zabihullah Mujahid confirmed the group had killed Afghan Air Force Major Dastagir Zamaray, and that it had started a program that will see the Afghan Air Force pilots “targeted and eliminated because all of them do bombardment against their people.”

A U.N. report documented 229 civilian deaths caused by the Taliban in Afghanistan in the first three months of 2021, and 41 civilian deaths caused by the Afghan Air Force over the same period.

In response to questions from Reuters, Taliban spokesman Zabihullah Mujahid confirmed the group had killed Zamaray, and that it had started a program that will see Afghan Air Force pilots “targeted and eliminated because all of them do bombardment against their people.”

Afghanistan’s government has not publicly disclosed the number of pilots assassinated in targeted killings and the Defense Ministry did not respond to requests for comment by Reuters.

The Pentagon meanwhile told Reuters it was aware of the deaths of several Afghan pilots in killings claimed by the Taliban, but declined to comment on U.S. intelligence and investigations.

Afghan military pilots are particularly attractive assassination targets, current and former U.S. and Afghan officials say. They can strike Taliban forces massing for major attacks, shuttle commandos to missions, and provide life-saving air cover for Afghan ground troops. Pilots take years to train and are hard to replace, representing an outsized blow to the country’s defenses with every loss.

Shoot-downs and accidents are ever-present risks. Yet these pilots often are most vulnerable in the streets of their own neighborhoods, where attackers can come from anywhere, said retired U.S. Brigadier General David Hicks, who commanded the training effort for the Afghan Air Force from 2016 to 2017.

“Their lives were at much greater risk during that time (off base) than they were while they were flying combat missions,” Hicks said.

Although Taliban assassinations of pilots have happened in years past, the recent killings take on greater significance as the Afghan Air Force is tested like never before, Reuters reported.

“Pilots are on top of the Taliban’s hit list,” the senior Afghan government official said.

That Afghan official and two others, speaking on condition of anonymity, said they’re working to protect pilots and their families, moving some to on-base housing and relocating others to safer civilian neighborhoods.