In Washington , the Metro Transit Police Department sent an e-mail to employees Friday night . NEW : No additional security at national monuments in Washington , the police say . New York and San Francisco officials say they 're stepping up their presence . Washington officials emphasize there is no specific threat . It 's a response to the concerns that shuttered some U.S. diplomatic sites .
NEW : No additional security at national monuments in Washington , the police say . New York and San Francisco officials say they 're stepping up their presence . Washington officials emphasize there is no specific threat . It 's a response to the concerns that shuttered some U.S. diplomatic sites .