Mexican authorities are investigating the disappearance of three Italian men in the western state of Jalisco.
Vicenzo Cimmino, Raffaele Russo and Antonio Russo - all from Naples - were last seen on 31 January in the Tecalitlán municipality.
Some reports say the Italians went missing after being detained by police at a petrol station.
Italian diplomats are helping the investigation, the Mexican authorities say.
Mexican investigators said the three men were in Jalisco "for business", but did not specify what that business was.
Last weekend, family members and friends of the missing men marched on the streets of Naples, demanding answers from the Mexican government about what had happened to their loved ones.
Last year was Mexico's most violent year on record, with more than 25,000 murders.
Organised crime - and feuding drug cartels in particular - accounts for nearly three-quarters of those deaths, officials say.
The US State Department in its most recent advisory urges travellers to reconsider going to Jalisco, warning that "violent crime and gang activity are common in parts of Jalisco state".