More than 60 people were reportedly killed in an airstrike on a bakery in Hama province in central Syria on Sunday.
The Syrian Observatory for Human Rights in London earlier said there was no exact figure because of confusion over the numbers of dead and wounded.
An amateur video distributed by the group showed a bombed one-storey building and a crater in the road beside it. The images have not been verified.
The group said the death toll could rise as 50 wounded people were in a critical condition.
The strike was in Halfaya, a town recently seized by rebels in a new push to take territory in Hama.
The BBC reports Halfaya was declared Halfaya a "liberated area" five days ago.
Rebels in Syria have been fighting President Bashar al-Assad for 21 months. Opposition groups say more than 44,000 people have been killed.