MEXICO CITY — At least 12 people died on Tuesday when a bus carrying cruise ship passengers to Mayan ruins in eastern Mexico flipped over on a highway, officials said.

Seven Americans and two Swedes were among the injured, said Vicente Martin, a spokesman for Quintana Roo State’s civil defense office. He said authorities had not yet established the nationalities of the dead.

Video images from the scene showed the bus on its side off the two-lane highway, with some survivors lying on the pavement

The Miami-based Royal Caribbean Cruises said in a statement that passengers from two of its ships, the Celebrity Equinox and the Serenade of the Seas, were involved in the crash.