Global Affairs Canada says at least one Canadian family has been affected by a bus crash in eastern Mexico that has killed an estimated dozen people.

The department says it is providing consular assistance to the family, but could not provide further details about how many Canadians were in the bus and whether they were killed or injured.

Authorities in Mexico say of the 31 people on the bus, at least 12 people were killed and 18 were injured Tuesday.

The bus was carrying cruise ship passengers to Mayan ruins when it flipped over on a highway.

Quintana Roo state Civil Defence spokesman Vicente Martin says seven Americans and two Swedes were among the injured, but says authorities hadn't yet established the nationalities of the dead.

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