WASHINGTON (Reuters) - Sanctions on Myanmar and withholding of U.S. aid are among options for pressing that country s government to stop attacks on Rohingya Muslims, U.S. officials said on Thursday, adding that they must be careful to avoid worsening the crisis.  We don t want to take actions that exacerbate their suffering. There is that risk in this complicated environment,  Deputy Assistant Secretary of State Patrick Murphy told a U.S. House of Representatives Foreign Affairs Committee hearing. Hundreds of thousands of Rohingya Muslims have fled Myanmar s Rakhine state since security forces responded to Rohingya militants  attacks on Aug. 25 by launching a crackdown the United Nations has denounced as ethnic cleansing. Myanmar rejects that accusation, insisting action was needed to combat  terrorists  who killed civilians. But it has left the world community counting the cost as international organizations and the government of Bangladesh, which has taken in the vast majority of the refugees, race to provide food, water and medical care. Many U.S. lawmakers have clamored for a strong U.S. response to the crisis and criticized government leader Aung San Suu Kyi, a Nobel peace laureate once hugely popular in Washington, for failing to do more. Representative Ed Royce, the Foreign Affairs committee s Republican chairman, said her recent statement denying that the military had conducted  clearance operations  was  factually false  and said she should speak out.  Those responsible for these atrocities must face justice. She and the military generals must rise to this challenge. This is ethnic cleansing,  Royce said. Representative Eliot Engel, the committee s top Democrat, was one of several committee members who said Washington should reconsider its decision to ease sanctions on the country and military. In particular, they called on Myanmar to allow international inspectors access to Rakhine State.  We re sitting here in our white shirts and our suits and these people are being slaughtered and thrown out of their country,  Republican Representative Scott Perry said.  Somebody needs to take action,  he added. Murphy said efforts were under way to identify individuals responsible for rights violation. Representative Ted Yoho, chairman of the panel s Asia subcommittee, asked if it would be effective to suspend aid to Myanmar s government until they allowed U.N. inspectors into Rakhine state. Kate Somvongsiri, a witness from the U.S. Agency for International Development, said that would be considered.  With the gravity of the situation, we obviously need to look at all the possible tools of leverage on the table,  she said. 