Updated

A cargo plane carrying equipment for African Union peacekeepers in Somalia caught fire and crashed into Uganda's Lake Victoria shortly after takeoff Monday, killing all 11 people on board, authorities said.

The victims were seven passengers — three senior Burundian military officers, two Ugandans, an Indian and a South African — and four Russian crew members, Information Minister Kabakumba Matsiko said.

The Ilyushin 76 was carrying water purifiers, pipes and other equipment for Ugandan troops who are part of an African Union peacekeeping force in Somalia, Ugandan army spokesman Maj. Felix Kulaigye said.

The cause of the crash was under investigation, the Ugandan Civil Aviation Authority said. Kulaigye said eyewitnesses reported seeing the plane catch fire in the air before it crashed into the lake.

Uganda has around 600 peacekeepers in Somalia, where the weak U.N.-backed government is battling an Islamic insurgency. It is preparing to send another 800 when funding for transport and logistics is in place. The peacekeepers guard the airport, port and main buildings where the Somali government is based, but not civilians.

Burundi has 1,700 soldiers in Somalia. Burundi army spokesman Adolphe Manirakiza said the three Burundian soldiers included Brig. Gen. Ndikumana Salum, who is the deputy commander of Burundian peacekeepers in Somalia, a colonel and a captain. He said the plane crashed five minutes after takeoff.

Air crashes are not unusual in Africa, where many airlines fly old or outdated aircraft — often from the former Soviet Union — and infrastructure is often not properly maintained. Some airlines are banned from flying in Europe.