As thousands of college students prepare for some spring break fun in the sun, violence is once again rising in one of the popular destinations: Mexico. Just this weekend three American diplomats, including a woman who was seven months pregnant, were gunned down in Ciudad Juarez. 31 people were killed in Acapulco.

Sergeant Kevin McNichols, with Arizona Department of Public Safety, said, "US citizens haven't been the primary target of a lot of the attacks that have taken place. It's been one drug cartel versus another cartel, but some of the US citizens have been caught in some of the crossfire."

That's why the U.S. State Department has issued a travel warning for six cities along the border, including Tijuana and Nogales. Safety officials say spring breakers shouldn't cancel their plans because not every tourist destination is dangerous. McNichols said, "In different parts of Mexico, there are different warnings for different areas, and so for the most part, we don't want to discourage anyone from traveling to or from Mexico."

Spring breakers are urged to travel in groups, keep a passport, license, and other forms of identifcation on them, and they should know and obey foreign laws to avoid harsh punishment. McNichols said, "Realize that your rights as an American citizen do not necessarily apply in some of the other countries, whether it be Mexico or another country that they maybe visiting over their spring break."

The young travelers are also advised to stay in well-lit, populated areas, and most of all stay in contact with friends and family back home. McNichols said, "Let some family members know where you're going to go and about what time they can expect you back so that way if something does happen, family and friends have agood idea of when to start to realize something could be wrong."

The travel warning stays in effect until April 12th. You can log onto the U.S. State Department's website to see if any other cities are added to the watchlist in the future at www.travel.state.gov.