( CNN ) -- Six people , including one minor , were killed Sunday in a natural gas explosion at a resort in Playa del Carmen , Mexico , authorities and state media reported . Another 15 or so were injured , according to the local attorney general 's office , with the injured including employees of the hotel and tourists from Canada and the United States . The U.S. State Department said two of those injured were Americans . One of the Canadian victims was a minor , Notimex , Mexico 's state news agency reported . Earlier , authorities had said that as many as 20 people could have been injured in the blast . The explosion was likely caused by a buildup of natural gas that somehow ignited , but the official cause is under investigation , the attorney general 's office said . Police Commander Arturo Guillermo had said earlier that a gas line or stove exploded at the Grand Riviera Princess . Video from the scene on Mexico 's east coast showed debris spilled into a grassy area in front of an area covered by thatched roofs where the restaurant presumably sits . The explosion happened around 9 a.m. Sunday morning in the lobby of the hotel . Emergency personnel responded and transferred the injured people to an area hospital for treatment . `` Right now we have personnel on site , '' said U.S. State Department spokeswoman Gini Staab . The two injured Americans were taken to a hospital , she said . Authorities , including consular agents and a consular officer , were on site at the hotel assisting U.S. citizens staying there , according to Staab . CNN 's Nick Valencia contributed to this report .
Four Canadians were killed . The attack was the deadliest in Canada since a gunman shot and wounded two soldiers at Canada's National War Memorial on Parliament Hill last October. At least one minor was killed in the explosion . It happened at the Grand Riviera Princess in Playa del Carmen .