Investigations have started into the cause of a military helicopter crash in Ghana which killed all eight people on board, including two government ministers.

Defence Minister Edward Kofi Omane Boamah and Environment Minister Ibrahim Murtala Muhammed were among those killed when the aircraft crashed early this month in the central Ashanti region. 

The defence ministry said on Monday that a board set up to investigate the crash had commenced work and has 30 days to submit its report, the Ghana News Agency reports. 

The board includes technical staff from the Ghana Air Force and the civil aviation regulator, a statement from the military is quoted as saying. 

It will be assisted by investigators from the US Air Force and may invite other technical personnel to join the investigation. 

Authorities previously said that the Z-9 helicopter that crashed was used as a utility helicopter, often used for transport and medical evacuation.

It had taken off from the capital, Accra, towards Obuasi, a gold-mining area in the Ashanti region, before it went off the radar.

The crash was one of Ghana’s worst air disasters in more than a decade.