CANCUN, Mexico >> Eight Americans, two Swedes and a Canadian were among those killed when the bus taking them from their cruise ships to visit Mayan ruins crashed in southeastern Mexico, officials said today. A tour guide was the 12th fatality.

The Quintana Roo state government said the injured also included three Canadians, four Brazilians and four Americans. Two Swedes were transported to the United States for treatment. Seven others slightly injured in Tuesday’s accident have returned to their cruise ship, officials said.

The injured bus driver was taken into custody, the government statement said. The cause of the crash was under investigation.

The Swedish and Canadian governments confirmed the deaths of their citizens today, but the U.S. Embassy in Mexico confirmed only “multiple” American deaths and several injuries. It said it had staff on the ground assisting victims and loved ones.

“We express our heartfelt condolences to all those affected by this tragedy,” said State Department spokeswoman Heather Nauert.

The bus flipped on a narrow highway in Quintana Roo state while carrying tourists to Mayan ruins.

Chris Brawley, of Haslet, Texas, was on one of the two cruise ships that had passengers on the crashed bus and was taking a different bus to the ruins. He said his bus passed by just minutes after the accident and he observed skid marks on the dry pavement.

Brawley said the ship he was sailing on, the Serenade of the Seas, sailed out of Mahahual Tuesday around 5:30 p.m., a couple hours after its scheduled departure. It was docked today up the coast in Cozumel.

“Captain informed us this morning one of our passengers passed overnight,” Brawley said.

AP writer Christopher Sherman in Mexico City contributed to this report.