He said that the combination of an ageing population and fire service cuts meant that "the installation of sprinklers is perhaps the single most effective measure in protecting occupants of dwellings from fire".

BBC: Why don't homes have sprinkler systems?

It said the embassy personnel had been heading to a military installation in the town of El Capulin when a carload of gunmen opened fire on them and chased them, along with the Mexican naval officer accompanying them.

BBC: Mexico police fire on US embassy staff