The US Embassy in Madrid has issued a warning to American citizens after what it says has been "a steady increase in the number of sexual assaults nationally over the past five years." The embassy says this includes a rise in sexual assault "against young US citizen visitors and students throughout Spain" and visiting Americans should take precautions, reports CNN. The embassy warns that American victims of sexual assault "can find it very difficult to navigate the local criminal justice system, which differs significantly from the US system." The warning follows the alleged rape of three sisters from Ohio in the city of Murcia on New Year's Eve, the New York Daily News reports. (More Spain stories.)