Syrians are being urged to rally against president Bashar al-Assad on the first Friday of Ramadan after the US turned up the heat on his regime over a crackdown it says has killed more than 2,000.
"God is with us, are you?" Internet-based activists said in a call for people to take to the streets in massive numbers yet again after the main weekly Muslim prayers.
The Assad regime has sought to crush the democracy movement with brutal force, killing more than 1,600 civilians and arresting thousands of dissenters, rights activists say.
Its latest crackdown has centred on the flashpoint protest hub of Hama, where at least 30 people were killed on Wednesday by tanks shelling the city centre. That prompted harsh words from Washington and Moscow, with Russia hinting at a possible change of heart after stonewalling firm UN action against Syria, its ally since Soviet times.