AMMAN (Reuters) - Protesters loyal to Syrian President Bashar al-Assad briefly broke into the US embassy in Damascus on Monday and security guards used live ammunition to prevent them storming the French embassy, diplomats said. No casualties were reported in the attacks but a US official said Washington condemned Syrias slow response and its failure to the prevent the assault on its embassy. The attacks followed a visit by the US and French ambassadors to the city of Hama last week in support of the hundreds of thousands of pro-democracy demonstrators who have been gathering there despite attacks by Syrian forces. We are calling in the Syrian charge (daffaires) to complain, said the US official. We feel they failed (in their responsibility to protect US diplomats). We are going to condemn their slow response. Human rights groups say at least 1,400 civilians have been killed since an uprising began in March against Assads autocratic rule, posing the biggest threat to his leadership since he succeeded his father 11 years ago.