A 39-year-old man was killed by a swarm of bees in northern Mexico after authorities failed to respond to emergency calls, the government news agency Notimex reported.

Juan Manuel Alaniz Gomez died of a heart attack on his way to a hospital Tuesday in Cuidad Obregon, 420 miles south of Phoenix, Notimex quoted local police official Edgar Jacobi Noris as saying.Jacobi Noris said the heart attack was caused by the bee stingsand that the swarm may have been Africanized killer bees, descendants of aggressive bees from Africa that escaped from breeding experiments in Brazil in 1956.