Syrian officials have denied reports that President Bashar al-Assad's motorcade came under attack Thursday as he traveled to a mosque in Damascus.
The rebel brigade Tahrir al-Sham said it fired artillery shells in the direction of the motorcade, and that some hit their target.
Information Minister Omran al-Zoubi called reports of an attack completely false.
State television broadcast video of Assad praying at a mosque in the capital Thursday, as part of the Eid al-Fitr holiday marking the end of Ramadan.
The Britain-based Syrian Observatory for Human Rights said mortar rounds hit the nearby Malki district of central Damascus, but did not confirm an attack on Assad's motorcade.
It is difficult to independently confirm events in Syria because of restrictions on international media.
Meanwhile, U.S. President Barack Obama says the United States is providing an extra $195 million in humanitarian aid for those affected by the Syrian conflict.
A U.S. statement Wednesday said Obama is timing the new aid to coincide with Eid al-Fitr, a holiday marking the end of Ramadan, Islam's holy month of fasting.
The statement said the additional aid will bring the U.S. humanitarian contribution to more than $1 billion since the Syrian crisis began more than two years ago. The aid will include food, medical assistance and hygiene kits, clothing and household supplies.
Aid agencies say Syria is facing a food crisis due to a poor harvest combined with critical shortages of staple goods caused by the country's civil war.
More than 100,000 people have been killed and about six million driven from their homes since the Syrian conflict began in March 2011.