Washington(CNN) The State Department warned US citizens against travel to Mexico's Playa del Carmen late Wednesday, a week after an explosive device was found on a tourist ferry in the area.

In an emergency message posted to the embassy's website, the agency said it had received "information about a security threat in Playa del Carmen," and that it is barring government employees from traveling to the resort town.

Playa del Carmen is a popular destination for American college students traveling for spring break, which many universities observe in March.

"US citizens must have as much information as possible to make informed travel decisions," State Department spokeswoman Heather Nauert said in a statement Thursday. "We take our obligation to provide information to US citizens seriously as evidenced by the clear, timely, and reliable safety and security information we release worldwide."

Nauert did not specify the nature of the threat. However, the State Department issued a separate emergency message last week notifying US citizens of an undetonated explosive device discovered on a ferry. That incident came about a week after an explosive device detonated on another ferry, injuring several passengers.

US officials have been in touch with Mexican law enforcement officials who are leading the investigation, Nauert said at a news briefing Thursday.

"Clearly, there is a threat," said Nauert. "We're making Americans aware of that threat so that Americans can protect their own safety and the safety of their families."