Cameron, Obama see 'increasing signs' of Syria chemical attack WASHINGTON (Reuters) - British Prime Minister David Cameron and U.S. President Barack Obama agreed on Saturday on the need to deter the use of chemical weapons, and were concerned about "increasing signs" that Syria attacked civilians, a spokesperson for Cameron said. "They are both gravely concerned by the attack that took place in Damascus on Wednesday and the increasing signs that this was a significant chemical weapons attack carried out by the Syrian regime against its own people," the spokesperson said. "They reiterated that significant use of chemical weapons would merit a serious response from the international community and both have tasked officials to examine all the options," the spokesperson said. Reporting by Mark Hosenball and Roberta Rampton; Editing by Peter Cooney