Authorities investigating an explosion in Mexico which killed five Canadian tourists have said a build-up of gas from a nearby swamp was responsible.

Two hotel workers were also killed following the explosion yesterday.

The blast in Playa del Carmen saw the floor of the building propelled through the ceiling and blew out windows, said the attorney general of Quintana Roo state.

Preliminary investigations indicated “an accumulation of gas caused by the decomposition of organic material” underneath the building caused the explosion, added Francisco Alor.

Among the dead are a man who was married days earlier and a father and his nine-year-old son.

Nine people remain in hospital.

Grand Riviera Princess Hotel

The area of the Grand Riviera Princess hotel – located in a region known as the Maya Riviera – was built four years ago.

The 676-room resort sits on a concrete platform on a swampy area near the beach - about 55 miles from Cancun.

A statement from Canada’s Foreign Affairs and International Trade department confirmed the death of one of the Canadians and said that officials had received unconfirmed reports that three Canadian citizens were missing and seven were injured.

Those who remain in hospital following the explosion include four Canadians, three Mexican employees of the hotel and two Americans, Mr Alor added.

Mexico’s Caribbean coast hosts about two million tourists every year, mostly from the United States, Canada and Europe.