On Monday, the Swedish aid organisation, Sida, said that one of its workers had been on the flight.
"It is with great sadness and pain that we have been told that a long-standing and highly appreciated colleague was on the passenger list on the plane that crashed on Sunday morning in Ethiopia. All our thoughts are now with our colleagues relatives, and with our colleagues in Sweden and in the countries where we work," Sida said in a statement.
Prime Minister Stefan Löfven offered his "deepest condolences" to the families of the 157 passengers and crew who were on board the Boeing 737 Max-8 aircraft which was heading for Nairobi, Kenya. Passengers from more than 30 countries were on the flight.
Sweden's foreign ministry is in contact with the ambassadors in Nairobi and Addis Ababa and says the relatives of the four Swedes have been informed.
While the cause of the crash has not yet been determined, Ethiopian Airlines has joined carriers in China and the Cayman Islands in suspending the use of the Boeing 737 Max 8. Last October, the same model of plane, operated by Lion Air, crashed in Indonesia, killing 189.
The model of aircraft is used by two airlines in Sweden. Tuis and Norwegian Airlines say they will continue to fly with the planes while the cause of the crash is being investigated.