The man, identifying himself as Colonel Riad al-Asaad, said in a telephone call to AFP in Nicosia that he was speaking from inside Syria "near the Turkish border."
"I am the commander of the Syrian Free Army," he said.
"We are hundreds," he added of the number of troops under his command.
|Anti-Syrian regime activists from different countries meet in Istanbul, on July 27, 2011.|
The claim could not be independently verified.
But the caller warned the Syrian regime against carrying out any security operations in Deir Ezzor, where activists said a massive military convoy, including tanks, deployed on Saturday.
"I warn the Syrian authorities that I will send my troops to fight with the (regular) army if they do not stop the operations in Deir Ezzor," Al-Asaad said.
Earlier the head of the Syrian Observatory for Human Rights based in Britain said soldiers shot dead three stone-throwers as a convoy of 60 military vehicles made its way towards Deir Ezzor.
Rami Abdel Rahman, quoting witness in the city, said the troops deployed in Deir Ezzor, with some of them taking positions near the offices of the governor.
Deir Ezzor is at the forefront of more than four months of anti-regime protests and scene of a deadly crackdown by the Syrian authorities against dissent.