US troops dumped gear during IS Afghanistan attack

American special operations forces working with Afghan partners in Afghanistan's Nangahar province had to abandon some of their gear when Islamic State jihadists attacked them, the Pentagon said.

The IS group has in recent days published a series of photos which appear to depict US equipment including bullets and magazines, grenades, a US flag and an American troop's photo identification.

According to the Pentagon, the troops had been involved in "actions" at a "casualty collection point," or CCP, when they came under enemy fire.

"As a result, the CCP was moved to a safer location. In the course of moving the CCP to a safe location, some equipment was left behind," Pentagon spokesman Adam Stump said.

"For understandable reasons, the lives of soldiers were not put at risk to recover the equipment prior to the scheduled exfiltration from the area at the already planned conclusion of the operation," he added.

Pentagon officials stressed that the US position was not overrun in the incident.

The Afghan army has intensified operations against IS in eastern Nangahar since the jihadists claimed two bombings last month in Kabul that left 80 dead and 231 wounded.

The Pentagon has said five of its special operations troops have been wounded in recent operations assisting the Afghans.

It was not clear if anyone was wounded in the incident involving the abandoned military kit.

"To protect the privacy of those involved, we won't comment on any specific injuries," Stump said.

"And, in an effort to protect capabilities, we won't discuss the specifics of any of the equipment pictured.