Two British service personnel were killed and one was injured today as two helicopters crashed north of Baghdad, the British Ministry of Defence said.
It was initially reported by the US Military that the two helicopters were American.
British Defence Secretary Des Browne said in a statement that an investigation into the incident was under way, but that initial reports indicated the crash was an accident "and not as a result of an attack by insurgents".
The service personnel's next of kin have been informed, but their names have not been released.
The crash happened south-west of Taji, 12 miles (20 kilometres) north of Baghdad, a US military statement said earlier.
Two Puma helicopters were involved in the crash.
Three other service personnel were slightly injured in the crash, a defence ministry spokesman said.
The identities of the service personnel were not released.
"I can't talk about the particular mission they were involved in, but we do have units operating as part of the coalition across Iraq," the spokesman said on condition of anonymity, in line with government policy.