Syrians took to the streets of Homs where at least 10 people were killed yesterday, activists said, as the opposition warned of the danger of a “massacre” by regime forces ringing the protest hub.

Four children were among 24 people killed when security forces and pro-regime militias opened fire in several cities across the country after the main weekly Muslim prayers, the Syrian Observatory for Human Rights reported.

Pro-democracy activists had called on citizens to turn out in support of a “dignity strike... which will lead to the sudden death of this tyrant regime.” Ahead of the demonstrations, the opposition Syrian National Council warned of a bloody final assault on Homs using the pretext of what the regime had called a “terrorist” attack on an oil pipeline.

“The regime (is) paving the way to commit a massacre in order to extinguish the revolution in Homs,” said the SNC, a principle umbrella group drawing together Assad’s opponents. Homs, an important central junction city of 1.6 million residents mainly divided along confessional lines, is a tinderbox of sectarian tensions that the SNC said the regime was trying to exploit. “The regime has tried hard to ignite the sectarian conflict using many dirty methods, which have included bombing and burning mosques, torturing and killing young men, and kidnapping women and children,” said the SNC.

Witnesses on the ground in Homs, already besieged for months, have reported a buildup of troops and pro-regime “Shabiha” militiamen in armoured vehicles who have set up more than 60 checkpoints, said the opposition group.