Formation of Syrian National Coalition announced amid reports of deaths in explosions in Deraa and air raids in Douma.
Syrian opposition groups meeting in the Qatari capital have agreed to form a united group called the Syrian National Coalition.
The biggest group, the Syrian National Congress, had been under pressure to join a broad-based government-in-waiting.
Saturday’s developments in Doha came at the same time as reports of dozens of people getting killed or injured in explosions in the southern Syrian city of Deraa.
Suicide bombers were thought to have targeted a military camp, killing at least 20 Syrian troops.
Meanwhile, the city of Douma, near the capital Damascus, has been hit by government fighter jets.
In one of the air raids, a hospital and surrounding buildings were destroyed. It is believed the hospital was empty before the attack.