Mexican authorities have confirmed five Canadians, including a young boy, were killed in a gas explosion that rocked a Mexican resort hotel on Sunday.

Local authorities said the Canadians were among seven people killed in the blast that took place in the lobby of the 676-room Grand Princess Riviera Hotel in the city of Playa del Carmen around 9:30 a.m.

Eight Canadians were also injured, including two listed in critical condition.

The explosion blasted chunks of flooring through the roof and left a crater a metre deep inside the building. It also blew out windows and hurled pieces of stone paving and glass shards about 50 metres onto the palm-fringed lawn of the compound.

Jesus Puc, director of the civil protection agency, said a nine-year-old boy, a 51-year-old man and two other men between 25 and 30 years old were among the Canadians killed in the explosion.

Francisco Alor, attorney general for the state in which the city is located, said initial investigations were focusing on the possibility that naturally occurring gas from a nearby swamp had built up under the hotel and somehow ignited.

The resort is hosting a large number of Canadians from various provinces, including at least one wedding and company vacation.

St. Catharines, Ont-resident guest James Gaade told The Canadian Press he was walking on the beach when he heard a loud explosion and saw smoke coming from the platinum lounge, a part of the resort which costs extra.

"I looked and you could see that the roof (of the restaurant) had collapsed. There was a large crater in the area, debris," he said.

"Everyone said their hotel room shook. The glass at neighbouring restaurants all cracked and blew out. The tiki hut that was in the area, that was on fire."

He estimated about 50 to 70 per cent of about 2,000 guests staying at the resort were Canadians and said he's met people from Ontario, Alberta, Winnipeg and Quebec.

Pete Travers, program director of 570 News Radio in Kitchener, Ont., is at the hotel with a large group of Canadians from nearby Waterloo. He said all 60 members of his group were accounted for.

Travers recalled hearing a huge crash before he went down for breakfast. He stepped into the hallway to find people running away from the blast site as word of an explosion rippled across the resort.

"There was quite a lot of chaos," he told The Canadian Press in an interview.

Travers and a few other guests rushed to grab deck chairs from the pool area to use them as make-shift stretchers for the injured.

"There was blood and injuries from flying glass and debris. No way of knowing just how injured these people were," said Travers. "I saw three or four people receiving triage, they appeared to my eyes to be tourists."

By Sunday evening, military and fire service vehicles remained at the hotel and the blast site was still off limits but guests appeared to be getting over the frantic panic of the morning.

"People are sitting around the pool so it appears to some degree that life is returning to normal here as best it can," said Travers.

But, he added a few of the Canadians he knows were making plans to cut short their stay and were planning to leave later Sunday or Monday.

Canada's department of Foreign Affairs says it was closely monitoring reports of the "accidental explosion."

Spokeswoman Lisa Monette said the Canadian Consulate in Playa del Carmen is ready to provide consular assistance to Canadian citizens as required.

Hotel staff have cleared out the main building, the lawn in front of the blast site, and an adjoining building. Guests whose rooms are now off-limits are being moved to different parts of the resort. A receptionist wouldn't provide details but said staff were working to deal with the situation as best they could.

Cheryl Harris has a 20-year-old daughter who is at the hotel with a group of friends for a wedding.

The Red Deer, Alta., resident said she first heard of the blast when her daughter sent her a message on Facebook.

"She said there had been an explosion, and she and the group she was with were safe," said Harris. "There was rumours of deaths ... and a building that had collapsed."

Harris said she doesn't know if the wedding, which has drawn guests from all over Alberta, will go ahead on Tuesday. She couldn't reach her daughter on her cell phone.

"I'm just really glad that she's safe. You don't really realize the enormity of what has gone on," said Harris. "When she said there was deaths, well, I'm glad they're ok."

The 45-year-old mother said it was somewhat of a relief to hear the blast wasn't an intentional one.

"As long as it's not anything drug, bomb related," said Harris. "A gas explosion can happen anywhere."

Canadian's at the resort who need emergency assistance can call the Canadian consulate at +52 (984) 803-2411, or call foreign affairs' emergency operations centre 613-996-8885. An email can also be sent to