Hard-line rebel groups in northern Syria have rejected the newly formed opposition coalition.
In an online video statement, 13 radical Islamist factions rejected what they called a "foreign project."
The groups declared their base in the northern city of Aleppo an "Islamic state."
The video appears to be a reaction to the formation of the Western-backed Syrian National Coalition for Opposition and Revolutionary Forces.
It was formed last week to unify groups trying to topple the regime of President Bashar al-Assad.
Its leader, Mouaz al-Khatib Monday announced his headquarters will be based in Cairo.
However, an official statement after his meeting with Egyptian Foreign Minister Muhammad Amr made no reference to it.
Meanwhile, Italian Prime Minister Mario Monti said on November 19 on a trip to Qatar that Italy was recognizing the new Syrian opposition council, but had not yet decided to give it full diplomatic recognition.
France and the six-nation Gulf Cooperation Council have given the coalition full diplomatic recognition.
Based on reporting by Reuters, AFP, dpa, and AP