Guests look out from a balcony to the site of a gas explosion inside a hotel in Cancun November 14, 2010. REUTERS/Stringer

CANCUN, Mexico (Reuters) - At least five Canadian tourists and two workers were killed on Sunday in a gas explosion that ripped through the restaurant of a hotel on Mexico’s Caribbean coast, authorities said.

A child was among the dead at the Grand Riviera Princess hotel in the beach resort of Playa del Carmen, Francisco Alor, the attorney general for Quintana Roo state, told Reuters by telephone.

Alor said 17 people were hurt -- seven Canadians, two Americans and eight Mexicans. Two of the Canadians were seriously injured, he added.

“Under no circumstances are we talking about an attack. It was an explosion of gas and we are determining the causes,” Alor said.

Officials from the Canadian embassy were not immediately available to comment.

Authorities said preliminary evidence pointed to an accumulation of gas beneath the floor of the restaurant. The blast blew pieces of the floor, glass and chairs out onto the manicured, palm-lined lawns of the sprawling hotel complex.