Victims of a chemical weapons attack in Syria last month were flown in secret to the United Kingdom to undergo tests, the Sunday Times has quoted a Syrian opposition leader as saying. According to the report in the British newspaper, the medical tests revealed traces of the deadly sarin gas in the systems of people caught up in the August 21 attack on the outskirts of Damascus. As many as three people were taken to Britain for the tests, the report said, adding that the results of the tests had been used by the UK as evidence against the regime of Syrian President Bashar Assad. US President Barack Obama is trying to build international and domestic support for military action against the Syrian regime, which is widely believed to have carried out the attack. On Saturday, CNN aired footage it said was of a chemical attack in Syria, and shown by Obama to members of Congress as he made his case for action.