Beirut, Lebanon (CNN) -- Rescue crews searched feverishly in poor weather conditions Monday for passengers from an Ethiopian Airlines flight that crashed into the Mediterranean Sea minutes after takeoff with 90 people aboard.

By Monday morning, crews had found nine bodies, but no survivors, off the Lebanese coast where the Boeing aircraft had gone down, the Lebanese government said.

Prime Minister Saad Hariri announced a day of mourning for the victims of the crash, ordering all government departments to close, the national news agency reported. He praised security forces and the Red Cross for their efforts in the aftermath of the accident.

Ethiopian Airlines Flight 409 left Rafik Hariri International Airport in Beirut about 2:30 a.m. and was headed to the Ethiopian capital, Addis Ababa.

It disappeared from radar a few minutes after takeoff, said Ghazi El Aridi, Lebanon's minister of public works and transportation.

Authorities did not immediately know the cause of the crash.

"We don't believe that there is any indication for sabotage or foul play," Lebanese President Michel Sulayman said.

"An investigative team has already been dispatched to the scene and we will release further information as further updates are received," the airline said, according to the Ethiopian News Agency.

The Boeing 737-800 had seven crew members and 82 passengers -- 51 Lebanese nationals, 23 Ethiopians, two Britons, an Iraqi, a Turk, a Syrian, a Canadian, a Russian and a person from France, the airline said.

An earlier tally provided by the Lebanese government varied slightly.

Among the passengers was the wife of the French ambassador to Lebanon, said Anne Charlotte of the French embassy.

Authorities did not immediately know the cause of the crash.

The plane crashed about 3.5 km (2.1 miles) west of the town of Na'ameh. Na'ameh is 15 km (9 miles) south of Beirut.

As worried family members gathered at the Beirut airport for news, the army and the U.N. Interim Force in Lebanon continued to scour the crash site for survivors.

"We hope that we will be able to rescue as many survivors, but the weather conditions are very bad," Sulayman said.

Government-owned Ethiopian Airlines is one of the largest in Africa.

Unlike several African carriers that are not allowed in European air space because of shoddy safety records, Ethiopian Airlines serves Europe. It serves three other continents as well, for a total of 56 destinations.

The airline has such a commendable safety record that some expanding airlines in Asia have lured away its pilots at high pay, The New York Times reported in 2006.

The airline has experienced two fatal crashes since 1980.

In November 1996, a flight bound for Ivory Coast, also known as Cote D'Ivoire, was hijacked by three men who demanded that the pilot fly to Australia. The pilot attempted an emergency landing near the Comoros Islands off Africa as the plane ran out of fuel, but crashed. About 130 of the 172 people aboard died, according to published reports.

And in September 1988, a flight struck a flock of birds during takeoff. During the crash landing that followed, 31 people of the 105 people aboard died.