Thousands of anti-government protesters have taken to the streets across Syria after Friday prayers, in defiance of the ongoing crackdown on dissent. At least 27 people were killed when security forces opened fire on a crowd of about 50,000 people in the central city of Hama, activists said. The opposition has dedicated the day to the memory of more than 30 children said to have died in the uprising. The army is meanwhile continuing its assault on the central town of Rastan. Scores have been killed in the past few days as troops and tanks attempted to quell protests there. At least two civilians died on Friday, the Local Co-ordination Committees said.