The explosion which killed six people and injured 20 others at a hotel in the Mexican resort of Cancun Sunday morning was an accident instead of an attack, local authorities said.

Quintana Roo State General Justice Prosecutor's Office (PGJE) said in a statement that the blast at Princess Riviera Maya was apparently caused by gas accumulation in the restaurant of the hotel, and one of the survivors had told police the fire and the explosion occurred during maintenance works.

The PGJE said that four of the six dead were Mexicans and the other two were Canadian tourists. No Italian citizen died in the incident as local press claimed earlier.

Authorities are checking identities of the injured, but they had said most of them were hotel employees.