A military helicopter has crashed at the NATO base in the Afghan capital, Kabul, killing five coalition members and injuring five others, authorities have said.
A statement from the Resolute Support Mission did not give the nationalities of those killed and injured, all of them NATO personnel.
However, Britain's Ministry of Defense said two Royal Air Force members were among those killed when the Puma Mk 2 helicopter crashed while landing at the base, where Afghan security forces are being trained.
The mission statement said the helicopter "crashed due to a non-hostile incident" around 4:15pm (11:45 GMT) on Sunday at Camp Resolute Support in Kabul.
In London, the Ministry of Defense also said a convoy of British military vehicles came under attack earlier on Sunday in a separate incident in the capital, but there were no fatalities.
General Abdul Rahman Rahimi, Kabul's police chief, said an explosion targeted a NATO military convoy, wounding three civilians.
He said the blast targeted two armoured vehicles attached to the NATO Resolute Support mission, damaging one of them. He did not specify whether the vehicles were British.
While Rahimi and a Taliban spokesman said the convoy was attacked by a suicide car bomber, US Army Colonel Brian Tribus, the spokesman in Afghanistan for US and NATO forces, said it was a roadside bomb.
The discrepancy could not immediately be reconciled.
The Interior Ministry said in a statement that the three civilians suffered minor wounds. It said the blast damaged surrounding buildings.
Taliban spokesman Zabihullah Mujahid sent a statement to local media claiming responsibility.
There have been a number of attacks in the capital in recent weeks, including one on October 6 targeting the house of former Helmand governor Nahim Baloch.
After an all-night battle, 10 people were wounded, including three civilians and seven members of the Afghan security forces. Officials said Baloch was not at home at the time.
The Taliban have been active across the country this year, most recently storming the northern city of Kunduz and holding it for three days before largely retreating in the face of a government counter-offensive.
In the helicopter crash, the aircraft appeared to strike a monitoring balloon as it landed at the NATO base, according to Najibullah, an Afghan security guard who witnessed the incident. Like many in Afghanistan, he goes by one name.
The helicopter "hit the cable of the security balloon over the base. It seemed like the cable was turned around the helicopter rotor", he said. Najibullah said the helicopter went down and then black smoke rose from the area.
A second helicopter circled around the area three or four times and then landed at a nearby airport, he said.
Tribus would only say that an "incident" involving a NATO aircraft and an observational balloon had taken place "in the vicinity of the Resolute Support base" in central Kabul.
The monitoring balloon was severed from its mooring in the incident, he said, without providing further details.