Mexican drug wars and a string of bloody murders have prompted the U.S. State Department to warn travellers - particularly students - to be careful on their spring breaks.

Canada's Department of Foreign Affairs hasn't made a similar warning, but its website urges travellers to careful of where they go in Mexico.

The State Department stopped short of warning spring-breakers not to go to Mexico, but advised them to avoid areas of prostitution and drug-dealing and to use common sense.

"Sage advice," said Tom Mangan, a spokesman for the federal Bureau of Alcohol, Tobacco, Firearms and Explosives. "We have had documented violence, attacks, killings, shootouts with the drug cartels involving not only the military but law enforcement personnel."

At least 30 Canadians have been killed in Mexico in the past 15 years. Perhaps the most notorious were the 2006 murders of Domenico and Nancy Ianiero of Woodbridge. their throats were cut during an attack in their resort hotel room.As recently as 2008, a man was shot and killed and his girlfriend wounded in what Mexican police called a random attack.

A surge of violence of late has been confined for the most part to border towns, but there have been murders in Acapulco and Cancun — popular spring break destinations.

Mexico's drug cartels are waging a bloody fight among themselves for smuggling routes and against government forces, carrying out massacres and dumping beheaded bodies in the streets.

But Mexican President Felipe Calderon on Thursday rejected U.S. concerns that Mexico is losing control of its territory to drug cartels.