As of 2002, armed forces strength was 7,350, of whom 6,900 were in the ground forces, 50 in the marine forces, and 400 in the air forces, (all considered part of the army). The army was equipped with 33 main battle tanks, the air force had 16 combat aircraft and no armed helicopters, and the navy possessed 3 river patrol boats. Paramilitary forces number 4,800, including a gendarmerie of 1,800, a republican guard of 2,000, and a national police force of 1,000. Mali participated in peacekeeping efforts in the DROC and Sierra Leone. In 2001, Mali spent $50 million on defense, or 2% of GDP.