Ghana's President John Mahama has promised a full investigation into Wednesday's helicopter crash that killed two government ministers and six other people.

Ghana’s defense and environment ministers are among eight people killed after a military helicopter crashed in the southern Ashanti region on Wednesday, according to the chief of staff to the Ghanian president.

The helicopter had taken off from Accra, the capital, en route to a mining conference when it went “off the radar,” the armed forces said.