Syrian opposition groups signed an initial agreement in Doha on Sunday to form a new coalition of forces fighting to end the rule of President Bashar Assad, a Syrian delegate at talks in Doha said on Sunday.

"An initial deal has been signed. The evening session will be for electing the president of the body and his deputy," Ali Sadreddine al-Bayanouni, a Muslim Brotherhood delegate at the talks in Qatar, told reporters.

The new body, made up of groups inside and outside Syria, will be called the Syrian National Initiative.

Earlier on Sunday, Syrian helicopters and artillery bombarded the Ras al-Ain area near the border with Turkey, days after Free Syrian Army rebels captured it during an advance into the northeast, opposition campaigners said.

Helicopters fired rockets at a grain storage area near the village of Tal Halaf and shells hit the border crossing in the northeastern oil-producing province of Hasaka, home to a large proportion of Syria's Kurdish minority, 600 km from Damascus, the activists told Reuters.