A Syrian rebel brigade has said it targeted President Bashar al-Assad's motorcade as he headed to a Damascus mosque for prayers to mark the Muslim holiday of Eid al-Fitr, but footage broadcast by state television on Thursday showed him unharmed.

The Tahrir al-Sham rebel brigade, a unit of the Free Syrian Army, said in a statement: "After conducting reconnaissance [on] the timing and course of Bashar al-Assad's motorcade the area was hit with artillery. We pray to God and await the field report about the results."

After the statement, Syrian state television showed what it described as footage of Assad praying at Anas bin Malek Mosque in the Malki district, where his residence is located.

Islam Alloush of the Liwa al-Islam, another rebel brigade, had told Reuters earlier on Thursday that rebels fired rockets which hit Assad's motorcade on his way to attend the prayers.

"Assad was not hit but the information we have, based from sources within the regime, is that there were casualties within his entourage," Alloush said.

Other activists also reported rockets were fired into the Malki area, which was sealed off by security forces.

Syria's information minister denied the motorcade was hit by rebel rocket fire. "The news is wholly untrue," Omran Zoabi told Syrian state television.