The crash of a military helicopter in Ghana on Wednesday killed all eight people aboard including the West African country's defense and environment ministers and other top officials, the government said.

People could be seen trying to sift through the wreckage of the crash in the forest in Sikaman, Ghana near Adansi Akrofuom in the Ashanti Region Wednesday.

The Ghanaian military said the helicopter took off in the morning from the capital Accra, and was heading northwest toward the gold-mining area of Obuasi when it went off the radar.

The cause of the crash was not immediately known, and the military said an investigation was underway.

Defense Minister Edward Omane Boamah and Environment Minister Ibrahim Murtala Muhammed were killed alongside the vice-chair of the National Democratic Congress ruling party, a top national security adviser, and crew members.

Mourners gathered at Boamah's residence as well as at the party's headquarters, and Ghana’s government described the crash as a “national tragedy.”

State media reported that the aircraft was a Z-9 helicopter that is often used for transport and medical evacuation.

Wednesday’s crash was one of Ghana's worst air disasters in more than a decade. In May 2014, a service helicopter crashed off the coast, killing at least three people. In 2012, a cargo plane overran the runway in Accra and crashed into a bus full of passengers, killing at least 10 people.