Visa credit cards issued in Syria, by Syrian banks or those with branches in the country, have stopped working from Wednesday, bank officials and users told AFP.
"Clients were sent SMS messages Tuesday evening informing them they could no longer use their Visa cards in Syria, or even abroad if it was issued in Syria," said Wissam Abu Ghazala, director of a branch of Lebanon's Byblos in Damascus.
Ali Ismail, manager of the import-export company Medsea, linked the move to to US and other Western sanctions imposed on the Syrian regime over its deadly crackdown of anti-government dissent.
"This is what the Americans call smart sanctions targeting senior officials of the (Syrian) regime. Which means that either we are all senior officials or it's just a way of punishing all the Syrian people," he said.
US President Barack Obama and his Western allies for the first time last Thursday called on President Bashar al-Assad to resign and boosted sanctions against his regime after five months of a brutal repression of protests.