Syrian security forces opened fire on tens of thousands of protesters in the city of Darra, killing 25 and wounding hundreds, witnesses said.

State-run TV said 19 policemen and members of the security forces were killed when gunmen opened fire on them, the first significant claim of casualties by the Syrian government.

The protests were in response to calls by organizers to take to the streets every Friday to demand change in one of the most rigid nations in the Middle East. Marches were held across the country.

At least 32 protesters were killed nationwide, according to human rights activists. Amnesty International said the death toll from three weeks of protest now exceeds 170, according to AP.

The calls for reform have shaken the regime of President Bashar Assad, whose family has ruled Syria for more than 40 years.