Tributes are being paid to two British air force members killed in a helicopter crash in Afghanistan.

Flight Lieutenants Alan Scott and Geraint "Roly" Roberts died in the accident yesterday at a NATO base in Kabul.

They were among five people killed, while five others were injured.

Group Captain Simon Paterson is the station commander at RAF Benson:

All five killed were from Resolute Support, a NATO-led mission to train Afghan security forces following the stand-down of the International Security Assistance Force last year.

Around 500 British troops remain in Afghanistan as part of the mission.

The deaths bring the total number of British forces personnel or British military of defence civilians killed while serving in Afghanistan since the start of operations in October 2001 to 456.

US Army Colonel Brian Tribus, a military spokesman, earlier said an "incident" involving a NATO aircraft and an observational balloon had taken place "in the vicinity of the Resolute Support base".

The balloon was severed from its mooring during the incident, he said, without providing further details.

The Puma Mk 2 aircraft hit the security balloon, according to an unnamed Afghan official.

An Afghan security guard who witnessed the incident, Najibullah, also told the Associated Press that the helicopter appeared to hit the balloon as it was landing.

The aircraft "hit the cable of the security balloon over the base. It seemed like the cable was turned around the helicopter rotor", said Najibullah, who goes by one name.

UGC footage has emerged of a balloon falling after the helicopter came down.

Earlier on Sunday, at least three people were injured in a suicide attack on a convoy of British troops in Kabul.

Three civilians suffered minor injuries after the bomber drove his car into the armoured vehicle during rush-hour, causing slight damage to it.