"Conditions are awful for those suffering respiratory disease, which in Tijuana is 29 percent of the population," Asthma and Allergy Medical Association president Joaquin Esquer said.

Wildfires have killed 16 in southern California and on Saturday two others in northern Mexico.

Even under normal conditions, air pollution is choking for Tijuana's 1.3 million residents.

Emergency room doctors saw three times as many cases of conjunctivitis, asthma and other respiratory diseases as normal.

Fired burned 22 houses and dumped tonnes of ash on roofs in Tijuana, immediately across the border from San Diego, California.

Saturday's two victims died in Ensenada on the Pacific coast. The army sought to beat back flames crossing the US border.

Firefighters in Tecate, 50 kilometers (30 miles) east of Tijuana, said another fire that began in Dulzura, California crossed into the Mexican city but was brought under control without loss of human life.

TERRA.WIRE