Just a week after an explosion on the same ferry line.

Tourists have been warned to "exercise caution" after undetonated explosives were found on a ferry boat in Mexico, just a week after an explosion on the same line injured as many as 25 people — and after the ferry line was suspended by Mexican authorities.

Mexican law enforcement officials on Thursday discovered explosives on a Barcos Caribe tourist ferry that runs between the popular vacation destinations of Cozumel and Playa del Carmen, according to an advisory from the U.S. Embassy in Mexico. Just a week earlier, on Feb. 21, an explosive went off as a Barcos Caribe boat unloaded passengers traveling the same route, resulting in more than two dozen non-life-threatening injuries.

Officials said at the time that the first explosion may have been the result of a mechanical issue, but the U.S. Embassy attributed it to an "explosive device" in its advisory.

In light of the back-to-back incidents in Mexico, the U.S. Embassy has forbid all U.S. government officials from traveling via the tourist ferries, and has urged travelers in that area to stay aware of their surroundings, exercise caution and purchase travel insurance that specifically covers trips to Mexico, including medical evacuation.

The investigation remains ongoing, according to the U.S. Embassy's statement.