SAO PAULO - Brazilian World Cup host city Manaus has declared a state of emergency as the waters of an Amazon River tributary swell, though officials say they don't expect it to flood.

Manaus city hall spokeswoman Jacira Oliveira says the 180-day state of emergency that went into effect on Tuesday is just a preventive measure to assure swift access to emergency resources if the Rio Negro unexpectedly spills into the city.

She says that even if there are floods, they won't damage the Arena Amazonia stadium that will host four games, including England against Italy on June 14 and the United States vs. Portugal on June 22.