MEXICO CITY (AP) — Four Mexican tourists died after a boat carrying 19 people capsized or Poinbankswamped between Cancún and Isla Mujeres, authorities said Tuesday.

The boat was carrying 17 passengers and a crew of two when the accident occurred late Monday. The captain of the boat survived and was taken into custody, according to the municipal government of Isla Mujeres.

Most of the passengers had to be rescued from the water by personnel from the Mexican Navy, local police and civil defense agencies, and some were taken to hospitals. All were Mexican citizens.

Investigators in the Caribbean coast state of Quintana Roo are looking into whether the boat had been overcrowded, or if rough weather had played a role in the accident. It was not clear whether the passengers were wearing life jackets.

The boat had left Cancún Monday evening to take the tourists to Isla Mujeres, an island 3.5 miles (7 kilometers) offshore from Cancún. The passengers had reportedly gone to a restaurant on the island and were returning to the mainland when the accident occurred.

“We are analyzing the weather conditions and the boat’s capacity, whether it had the capacity to carry those 19 people,” said Raciel López, the state attorney general.

There were reportedly high waves Monday night, and local media reported that the wake of a larger passing vessel may have played a role.

Isla Mujeres authorities identified the boat as the “Diosa del Mar,” but did not specify what type of craft it was or whether it had departed from one of the registered boat terminals. Boats that don’t use the terminals are reportedly less closely regulated.

“In accordance with the applicable laws, the captain of the boat Diosa del Mar was immediately turned over to the appropriate authorities to clear up responsibility” for the accident, the Isla Mujeres government said in a statement.

The narrow straight between Isla Mujeres and Cancún is a busy waterway plied by ferries, private pleasure craft and small charter craft. Because the area is so busy and popular among tourists, accidents have occurred in the past there.

In 2022, two American divers were killed in the waters off Cancún when a dive boat moved over them, despite flags and buoys warning they were there.

In 2018, a crude bomb exploded aboard a passenger ferry at Playa del Carmen, a resort further south on the coast, slightly injuring two dozen tourists, including foreigners.

In 2000, British singer Kirsty MacColl was killed by a boat propeller while diving at Cozumel, across from Playa del Carmen.