A plane belonging to an air ambulance service has crashed in a residential area outside Kenya's capital, killing at least six people. The crash happened Thursday, according to a local official and the aircraft's owner. AMREF Flying Doctors said the Cessna Citation XLS took off from Nairobi and was heading to Somaliland when it crashed. The service provider didn't specify the number of casualties or the cause, stating they're cooperating with authorities to establish the facts. A local official said four people on board and two in a house were killed. The Kenya Red Cross sent rescue teams to the scene.