A US air strike that destroyed a medical charity's clinic in northern Afghanistan, killing 42 people, was not a war crime, the Pentagon has said.

Confirming disciplinary charges against 16 US service personnel, General Joseph Votel said the "tragic strike" was due to human and technical errors.

A US gunship mistook the hospital at Kunduz, run by Medecins sans Frontieres (MSF), for a building that had been seized by Taliban fighters.

No-one will face criminal charges.

But as the error was "unintentional", it did not constitute a war crime, Gen Votel said, an accusation MSF has previously levelled at the US.

Instead, those punished were hit with measures such as suspension from command and letters of reprimand, which could end their military careers.

Gen Votel, the head of US Central Command, gave details of a US investigation, describing a crew tired from days of fighting taking off earlier than planned without the correct preparatory information.

About 10 minutes into the raid, MSF doctors on the ground rang US officials pleading for them to stop, but it was another 20 minutes before they ceased, he said.