MEXICO CITY, CBS News - At least 11 people died when a bus carrying cruise ship passengers to Mayan ruins in eastern Mexico flipped over on a highway early Tuesday, officials said. At least seven Americans are among the injured.
In addition, two citizens of Sweden are injured, according to Quintana Roo state Civil Defense spokesman Vicente Martin, who said authorities haven't yet established the nationalities of the dead.
A spokesman from the U.S. Embassy in Mexico said U.S. officials were working with local authorities to determine whether U.S. citizens were involved.
"We express our condolences to all those affected by this tragedy," the U.S. Embassy said. "We are in contact with local authorities and are working with them to determine if there were U.S. citizens on board. We will continue to monitor the situation."
The U.S. Embassy in Mexico also added: "The protection of U.S. citizens overseas is one of the highest priorities for the State Department. We stand ready to provide all appropriate consular assistance to affected U.S. citizens. Any U.S. citizens who require assistance may reach the Consular Service Center in Monterrey at +52-81-8047-3145."
Video images from the scene showed the bus on its side in vegetation off the two-lane highway, with some survivors lying on the pavement while others walked around.
Martin said the crash occurred as the bus was on its way to the ruins at Chacchoben, about 110 miles south of Tulum.
The cause of the accident was under investigation.
Costa Maya Mahahual, the bus company involved, said in a statement that the bus was carrying tourists who arrived to the coastal town of Mahahual.
In addition to the tourists, a guide and driver were aboard the bus, the company said.
The General Director of State Transit, Jorge Cesar Santana Poot, says injured people were transferred to hospitals in Bacalar and Chetumal.
Royal Caribbean said in a statement the accident is "heartbreaking."
"The news from Costa Maya about a bus accident involving our guests is heartbreaking," the statement said. "Our hearts go out to all those involved. We are doing all we can to care for our guests, including assisting with medical care and transportation."
Royal Caribbean reports that the tour bus involved was carrying guests from Celebrity Equinox and Serenade of the Seas.
Royal Caribbean has been active on social media in regards to the accident and its 27 guests who were on the bus: