Madrid (CNN)The US is advising its citizens to take precautions against sexual assault when visiting or studying in Spain, according to a security alert issued by the US Embassy in Spain.
The alert said the Spanish Ministry of Interior has reported "a steady increase in the number of sexual assaults nationally over the past five years."
"This includes a rise in sexual assault against young US citizen visitors and students throughout Spain," the alert added.
The advice follows the alleged rape of three American women in the city of Murcia, southeastern Spain, on New Year's Eve.
"US citizen victims of sexual assault in Spain can find it very difficult to navigate the local criminal justice system, which differs significantly from the US system," the embassy alert read.
Mass protests in Spain followed a controversial ruling in November which cleared five men of sexual assault charges, though a statement on the Barcelona court's website described the men taking turns performing sexual acts on an unconscious teenager.
The five were convicted of a lesser charge of sexual abuse.
Under Spanish law, a sexual attack can only be classified as an assault or rape if the perpetrator uses violence or intimidation.
