Syrian activists say rebels have killed at least 21 people at a campaign rally for President Bashar al-Assad in the southern city of Daraa.
The Syrian Observatory for Human Rights says the rebels shelled a tent where Assad's supporters had gathered late Thursday.
The Observatory's Rami Abd al-Rahman told VOA the victims include both civilians and pro-Assad militiamen.
"Twenty-one were killed. At least 11 of them are civilians. One of them was a child under 18. The other 10, six of them were (pro-regime fighters) and four of them we don't know if they were civilians or (pro-regime fighters)," said al-Rahman.
The London-based monitoring group, which relies on a network of opposition activists, said about 30 people were seriously wounded.
Rahman said he expects more attacks on campaign events as the June 3 election draws closer. Campaigning began earlier this month.
Assad is expected to easily beat his two little-known challengers and win a third term.
The Syrian opposition and many Western countries view the election as illegitimate and have vowed not to respect the results.