NAIROBI -- Four people were killed when a cargo plane crashed shortly after takeoff at the international airport in the Kenyan capital, Nairobi, a police official said Wednesday.

The Fokker 50 aircraft transporting the mild stimulant known as Khat to the Somali capital, Mogadishu, crashed into a residential building after taking off from Jomo Kenyatta International Airport early Wednesday, said Joseph Ngisa, the airport's head of police investigations.

Preliminary investigations found the plane was flying low after takeoff and might have hit an electrical pole before crashing in the Embakasi area of the city, Ngisa said.

No other details were immediately available on the possible cause of the crash.

The Kenya National Disaster Operation Center said on Twitter that all the victims were male, and they included the flight engineer as well the pilot and two crew members.