MEXICO CITY - Mexican officials said late Wednesday that the Caribbean resort city of Playa del Carmen is safe, despite a U.S. security alert.

The government of the Caribbean coast state of Quintana Roo said that President Enrique Pena Nieto was scheduled to attend an ocean conservation conference in Playa del Carmen on Thursday.

"All tourism and economic activity in Playa del Carmen continues in a normal manner," the state government wrote in a statement, noting that hotel occupancy at the resort was 80 per cent.

"We do not know why the U.S. government decided to emit this alert," the government said.

Playa del Carmen is near Mexico's most popular tourist destinations, like Cancun, Cozumel and Tulum.

The U.S. Embassy said it received information Wednesday about a "security threat" in Playa del Carmen and U.S. government employees are prohibited from going there, but it did not specify the nature of the threat.

It said the U.S. consular agency there "will be closed until further notice."

A Feb. 21 explosion on a tourist ferry in Playa del Carmen injured 19 Mexicans and at least five U.S. citizens.

After that, the U.S. Embassy barred employees from taking ferries between Playa del Carmen and Cozumel Island, one of the world's busiest cruise ship ports of call.

And last week, undetonated explosive devices were found on another boat owned by the same ferry company.

State prosecutors say the ferry incidents are under investigation. Local media say officials are examining several possible motives, including the possibility that people linked to the ferry company could have bombed the boat to collect an insurance policy.

The ferry company has not responded to requests for comment. But on March 4, the company issued a statement saying "referring to this as an attack from inside the company is a very low, morally unfounded act, which we categorically deny."

The area has also been hit, albeit infrequently, by drug violence.

Last week four gunmen burst into a hospital in Cancun and shot to death a drug gang suspect and his wife.

In January 2017, gunmen attacked the state prosecutors' office in Cancun, killing four people. A day earlier, a shooting at a music festival in Playa del Carmen left three foreigners and two Mexicans dead. Prosecutors have said that shooting was motivated by low-level drug sales.

News from © The Associated Press, 2018