British Foreign Secretary William Hague called on Syrian President Bashar al-Assad to stop the deadly assault on protesters in Hama on Sunday, saying he was "appalled" at the attacks on the eve of Ramadan.
At least 45 people were killed when the army launched an attack on the flashpoint protest city in central Syria, a human rights activist said, amid continuing demonstrations across the country against Assad's regime.
"I am appalled by the reports that the Syrian security forces have stormed Hama with tanks and other heavy weapons this morning, killing dozens of people," Hague said in a statement.
"Such action against civilians who have been protesting peacefully in large numbers in the city for a number of weeks has no justification.
"The attack appears to be part of a coordinated effort across a number of towns in Syria to deter the Syrian people from protesting in advance of Ramadan. The attacks are all the more shocking on the eve of the Muslim holy month."
In a warning to Assad, he continued: "President Bashar is mistaken if he believes that oppression and military force will end the crisis in his country. He should stop this assault on his own people now."