An investigation is under way after a huge gas blast devastated a resort hotel on Mexico's Caribbean coast, killing seven people including five tourists.
Two Mexican employees of the sprawling, 676-room Grand Riviera Princess hotel in Playa del Carmen, south of Cancun, were killed in the blast along with the five Canadian holidaymakers, said Francisco Alor, attorney general of the Quintana Roo region where the hotel is located.
Two other Canadians suffered severe injuries and are in a critical condition. Ten people, including two US citizens and eight Mexican hotel employees, have less serious wounds and are listed as stable.
Mr Alor described a horrific scene in which the floor of the building was effectively hurled through the ceiling by the force of the explosion, blowing out windows and sending fragments of aluminium window and ceiling panels over a wide area.
"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," said an eyewitness who was walking on the beach when he heard a loud explosion and saw smoke coming from the resort's premium platinum lounge.
Mr Alor said the dead included four men and a woman, while Playa del Carmen civil defence director Jesus Puc said the Canadian fatalities included a nine-year-old boy.
Initial investigations suggest the gas that exploded beneath the building was apparently a mix of gases from a nearby swamp, Mr Alor said. No gas pipes were located in the area.
He added that examinations will now take place to determine whether the hotel building, which sits on a concrete pad on a swampy area near the beach, had been properly constructed.
The resort was hosting a large number of Canadians at the time, including at least one wedding and a company break. It was estimated that 50-70% of the guests at the resort were Canadians.
Canada's Foreign Affairs and International Trade department said in a statement: "On behalf of all Canadians, the government of Canada extends its sympathies to the families and friends of those who lost their lives."