An Ethiopian Airlines Boeing 737 passenger jet has crashed on a flight from Addis Ababa to Nairobi in Kenya.

The flight is believed to have had 149 passengers and eight crew members on board, the airline says.

A spokesman said the crash happened at 08.44 local time on Sunday, shortly after take-off from the Ethiopian capital.

First word of the crash came when Prime Minister Abiy Ahmed expressed his "deepest condolences" on Twitter.

In a statement, the airline said that search and rescue operations were under way near the crash site around the town of Bishoftu, which is 60km (37 miles) south-east of the capital.

It did not provide details on the number of casualties.

"Ethiopian Airlines staff will be sent to the accident scene and will do everything possible to assist the emergency services," the statement added.

The airline flies to many destinations in Africa, making it a popular carrier in a continent where many airlines fly only from their home country to destinations outside Africa. 

It has a good reputation for safety, although in 2010 one of the company's aeroplanes crashed in the Mediterranean Sea shortly after leaving Beirut.

The incident killed 90 people on board.

The airline's highest fatalities to date came in a November 1996 crash during a hijacking on a flight from Addis Ababa to Nairobi.

One of the aeroplane's engines stopped when the fuel ran out and although pilots attempted an emergency water landing, they hit a coral reef in the Indian Ocean and 123 of the 175 people on board were killed.