A SAN Diego police sergeant has warned Irish students of the dangers of crossing the border into Mexico, where under-21s have been travelling to avoid US drinking laws.

Students as young as 18 are going to the crime-riddled city of Tijuana where muggings, kidnappings and drink-spiking are common. The charity Irish Outreach San Diego said drunken Irish students were being targeted by criminals who saw them as easy prey after drinking binges.

Sgt JJ Salinas, of the southern division, border crime suppression team in San Diego, said muggings and kidnappings were common, particularly when people are leaving the city’s busy nightclubs.

“Sometimes people are naive in that they don’t recognise the high level of violence that’s occurring right now in Mexico,” he said.

Tijuana has seen a fall-off in violence in the past two years, with the number of homicides falling from 820 in 2010 to 478 last year. However, it is still dominated by a violent drug cartel.

Bernadette Cashman of the Irish Outreach Centre in San Diego said a company was running bus tours to Tijuana for Irish under-21s. The bus leaves them at the border on Wednesday night and picks them up in the early hours of Thursday morning.

She said there was evidence drugs were being added to drinks there so the drinkers would be helpless by the end of the night.

Sgt Salinas said: “There have been incidents where people were taken to an ATM and forced to take out all their money.”