Five people, including two RAF personnel, have been killed in a helicopter crash in Afghanistan.

The Puma Mk2 helicopter crashed as it was landing at Nato's Resolute Support mission headquarters, Kabul. Nato has not released the nationalities of the other victims or the five left injured.

A Ministry of Defence spokesman said the crash was "an accident and not the result of insurgent activity".

The families of the British victims have been informed, the MoD said.

They have asked for a period of grace before their names are released.

The accident comes after a convoy of UK military vehicles was attacked in Kabul, the Afghan capital, on Sunday morning. Seven people were injured and there were no UK casualties, the MoD said.

The MoD has said an improvised explosive device caused an explosion, while officials in Kabul said it was a suicide bombing. The Taliban said it carried out the attack in retaliation for air strikes in Kunduz which killed civilians and doctors.

Observation balloon

The two RAF personnel killed in the helicopter crash were from 230 and 33 squadrons, both of which are based at RAF Benson, Oxfordshire, the MoD spokesman said.

He added: "The helicopter crashed while landing at the headquarters of Resolute Support: the Nato train, advise and assist mission in Afghanistan.

"The incident is currently under investigation but we can confirm that it was an accident and not the result of insurgent activity."

BBC defence correspondent Jonathan Beale said: "The BBC understands the RAF Puma that crashed in Kabul had been transferring Nato military personnel.

"Helicopter movements of military personnel are more frequent following attacks - such as the one that took place on a British military convoy earlier today.

"The cause of the crash is still being investigated but an observation balloon became untethered and landed in the Resolute Support base in Kabul."

The coalition aircraft crashed with 10 people on board, Resolute Support said in a statement.

"The incident resulted in the death of five Resolute Support personnel and the injury of five others," it said.

"It is Resolute Support policy to defer casualty identification to the relevant national authority. The incident is currently under investigation."

British combat troops pulled out of Afghanistan a year ago after a conflict that lasted 13 years and in which 454 UK troops lost their lives.

Nato's Resolute Support mission, which was launched after its combat mission ended, consists of more than 13,000 troops from 42 countries, including nearly 500 UK troops.

It focuses on training and supporting Afghan security forces and institutions after the International Security Assistance Force stood down last year.