(CNN) -- An Ethiopian airliner with 83 people on board crashed into the sea after takeoff from Lebanon early Monday, Lebanese army officials said.

The Boeing aircraft was en route from Beirut to the Ethiopian capital, Addis Ababa, when it disappeared from radar 30 minutes after takeoff from Rafik Hariri International Airport in Beirut about 4 a.m. local time, Lebanon's National News Agency reported.

On board were 54 Lebanese nationals and 29 people of other nationalities, the army officials said.

No additional information was immediately available.

