Morocco's King Mohammed has declared three days of national mourning following a military plane crash that killed 78 people.

The state-run MAP news agency says the plane crashed into a mountain Tuesday as the pilot was preparing to land in bad weather at a military airport near the southern town of Guelmim.

It says three people survived the crash but have serious injuries.

The government says the C-130 military aircraft carried 60 soldiers, 12 civilians and 9 crew members.

The plane was flying north from the disputed Western Sahara.

The crash is Morocco's worst aviation disaster in decades. King Mohammed released a statement extending his condolences to the families of the victims.