NAIROBI, Kenya (AP) — A plane belonging to an air ambulance service provider crashed in a residential area just outside Kenya’s capital on Thursday, killing at least six people, according to a local official and the aircraft’s owner.

AMREF Flying Doctors said that the mid-size jet, a Cessna Citation XLS, took off from an airport in Nairobi and was heading to the territory of Somaliland when it crashed.

The service provider didn’t provide the number of casualties or a possible cause, saying in a statement that it was “cooperating fully with relevant aviation authorities and emergency response teams to establish the facts surrounding the situation.”

The plane crashed in the residential area of Mwihoko in Kiambu County, which shares a border with Nairobi.

A local official, Kiambu County Commissioner Henry Wafula, told reporters at the scene that four people on board were killed in the crash. Two other victims were inside a house into which the plane crashed, he said.

The Kenya Red Cross said that its rescue teams headed to the crash scene in Kiambu, a county that shares a border with Nairobi. Earlier, the Kenya Red Cross had said that the aircraft that crashed was a helicopter.