MEXICO CITY (AP) — The latest on the crash of a bus carrying tourists in eastern Mexico (all times local):

3:30 p.m.

An American cruise passenger visiting Mexico says a bus that flipped over on the way to Mayan ruins crashed on a dry road and he didn't see any sign that other vehicles were involved.

Mexican officials say at least 12 people died in the crash, but their nationalities have not yet been determined. They say seven Americans and two Swedes were among the injured.

Chris Brawley of Haslet, Texas, says he didn't see the accident, but his bus of tourists came upon the scene minutes after the crash.

He says a convoy of buses was carrying people from the cruise port at Mahahual and heading to Chacchoben. He says they had been driving about 35 to 40 minutes before the accident.

Brawley says the sky was clear and the road was dry, and he did not see any other vehicles involved.

He did not see the crash, but says that "the bus clearly lost control somehow as there were swerve marks all over the road surface."


2:10 p.m.

Miami-based Royal Caribbean Cruises says that passengers from two of its ships have been involved in a fatal bus crash in Mexico.

Royal Caribbean says in a statement that passengers from the Celebrity Equinox and Serenade of the Seas were on the bus that flipped on a two-lane highway Tuesday morning.

Quintana Roo state Civil Defense spokesman Vicente Martin says 12 people were killed, though it's not clear if all were cruise passengers and their identifies and nationalities have not been released. He says seven Americans and two Swedish citizens are among those injured.

The bus was travelling to Mayan ruins at Chacchoben, about 110 miles (175 kilometers) south of Tulum.

A spokesman from the U.S. embassy in Mexico says diplomats are working with local authorities to determine whether U.S. citizens were involved.