Mortar rounds on Thursday hit an upscale district of Damascus where President Bashar al-Assad attended prayers to mark the start of a major Muslim holiday in a rare attack in the high security area.

A Syrian rebel brigade claimed it fired mortar shells that hit Assad's motorcade in the Malki district of the capital, but Syrian state TV broadcast images of the Syrian leader attending prayers and the information minister denied reports that the president had been attacked.

An Islamic rebel brigade, Liwaa Tahrir al-Sham, said it fired several 120 mm shells in the direction of Assad's motorcade after carrying out careful surveillance of its route.

The claim was made on the group's Facebook and Twitter pages and could not be independently confirmed. The brigade's head, Firas al-Bitar, told Al-Arabiya TV that the motorcade had been hit but that it was not certain whether Assad himself had been harmed.

Assad has a residence in the upscale district that has largely been sheltered from the shellings and battles that usually rage in the city's impoverished suburbs. However, it was not clear if Assad has stayed in Malki in recent months.

Information Minister Omran al-Zoubi dismissed the attack claims as "rumours" and told state TV that Assad drove his own car to the Anas bin Malik Mosque, located in the heart of Malki.

Assad's 3rd recent public appearance

It was the Syrian leader's third public appearance in over a week as his regime tries to capitalize on recent gains on the battlefield against rebels fighting to oust him from power.

In the state TV broadcast, Assad, dressed in a suit, was seen praying alongside Syria's grand mufti at the start of Eid al-Fitr, the three-day holiday that ends the holy month of Ramadan. The Eid prayers are typically an hour or two after sunrise. In previous years, Assad has been seen attending them early in the morning.

The Britain-based Observatory for Human Rights which closely monitors the fighting in Syria said only three mortar shells hit Malki early in the morning. The neighbourhood has rarely been targeted by opposition forces during the conflict, which last year brought the rebels and their battle to the heart of the capital.

There were no immediate reports of casualties or damage in the shelling, which was confirmed by Malki residents, who spoke on condition of anonymity fearing for their own safety.

Rami Abdul-Rahman, the Observatory's head, said he had no confirmation that Assad's motorcade had been hit and was skeptical of the reports.

Shells hit neighbourhood of Shia shrine

Syria's state news agency said several mortar shells also hit the capital's suburb that is home to the golden-domed Shia shrine of Sayeda Zeinab, the Prophet Muhammad's granddaughter, which is popular with Iranian worshippers and tourists. The attacks caused casualties, the SANA news agency said, but gave no details.

Assad's troops have recently been on the offensive in central Syria, making advances near the border with Lebanon and in the city of Homs, an opposition stronghold and Syria's third largest city.

On Wednesday, Syrian government troops ambushed a large group of rebels trudging through a desert road northeast of Damascus, killing more than 60 fighters.

In the north, where much of the territory has been under opposition control in the past year, rebels scored a rare victory earlier this week when they captured a major air base in the Aleppo province near the border with Turkey.

Syria's crisis started as a largely peaceful uprising against Assad's rule in March 2011. It turned into a civil war after opposition supporters took up arms to fight a brutal government crackdown. More than 100,000 people have been killed in the violence so far, according to UN figures.