Survivors of a US air strike on a hospital in Afghanistan have called for those responsible to go on trial and dismissed an American military investigation that said the bombardment did not amount to a war crime.

The Pentagon on Friday published a report of their investigation into the air strike saying the troops involved in the raid would not face war crimes charges.

The attack on the hospital run by medical charity Doctors Without Borders in the city of Kunduz last October left 42 people dead and triggered global outrage, forcing President Barack Obama to make a rare apology.

"They should be publicly put on trial," Hamdullah, a 27-year-old who lost his uncle in the attack and worked in the laundry at the hospital, told AFP.

"This was a deliberate bombardment by the American forces, and we are not satisfied that they have said this was not a war crime. This is unacceptable for us," Hamdullah, who goes by one name, said.

General Joseph Votel, the head of US Central Command, said an investigation had found those involved made a series of mistakes and hit the clinic in error.

"It's a joke that the US said the incident was not a war crime," Zahidullah, 24, who lost a cousin in the attack and worked as a cleaner at the hospital, told AFP.

"It is unacceptable to all of us", he added.

"What we saw that night is difficult for us to express in words," he said, calling for compensation for victims and their families as well as adequate medical care.

The hospital - the only health facility in the province - was forced to close after the attack.

The Afghan government in a statement welcomed the publication of the report.

"The Afghan government is satisfied that the investigation was done carefully and comprehensively, and believes measures were taken to ensure accountability," it said in a statement.

"The government of Afghanistan supports measures for preventing such attacks," it added.

The bombing last October came as Nato-backed Afghan forces clashed with insurgents for control of the northern provincial capital.

Doctors Without Borders branded the strike a war crime, saying the raid by an AC-130 gunship left patients burning in their beds with some victims decapitated and others requiring amputations.