Lines drop tours involving Cozumel ferries after security alertLines drop tours involving Cozumel ferries after security alert

This follows a security alert from the US Embassy in Mexico City after undetonated explosive devices were found March 1 by Mexican law enforcement on a tourist ferry that links Cozumel and Playa del Carmen. The US Embassy said an explosive device detonated on a tourist ferry in Playa del Carmen on Feb. 21, resulting in injuries, including to US citizens.

'We have canceled all ship-sponsored tours that make use of ferries between Cozumel and Playa del Carmen and we are strongly advising our guests that ferries from Cozumel to the mainland be avoided,' a Carnival spokeswoman said.

'In an abundance of caution we are canceling sponsored shore excursions that involve tourist ferries only,' a Royal Caribbean spokesman said. 'We are also discouraging our guests from taking part in independent excursions that involve ferry travel.'

Cozumel is the Caribbean's busiest cruise destination.