Updated

Investigators released new details Sunday about a tourist ferry blast in Mexico that injured 26 people — including several American citizens — Feb. 21 in the Caribbean resort city of Playa del Carmen, one of the country’s most traveled regions for tourism.

Mexican authorities say a rudimentary or homemade explosive device was responsible. But Deputy Attorney General Arturo Elias Beltran said Sunday at a news conference that terrorism and organized crime have been “ruled out.”

Federal prosecutors said there's no motivation for a terrorist group to have carried out an attack. They added that they did not believe criminal gangs would have done it, knowing it would draw unwanted attention and increased security.

Prosecutors also say an object found attached to the underside of another ferry belonging to the same company, Barcos Caribe, later near Cozumel Island is a similar “rudimentary artifact.”

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Emergency crews at the scene of the explosion at Playa del Carmen, Mexico. (Periodico de Peso via REUTERS)

Authorities are pursuing multiple lines of investigation.

Although the U.S. Embassy in Mexico claimed it was separate from the ferry blast, the agency narrowed its travel warning for Playa del Carmen last week, as Fox News reported, amid what it called an unspecified “ongoing security threat” — just as the spring holiday season is kicking into high gear.

In a notice posted Friday on its website, the embassy said the U.S. Consular Agency in the city would reopen and resume normal operations Monday after a shutdown of several days — “absent additional changes in the security situation.”

The Associated Press contributed to this report.