SAN JUAN, Puerto Rico (AP) — Puerto Rico’s National Guard was deployed to help fight a large fire at a landfill in the US Virgin Islands that has been burning for more than a week and which has forced schools and businesses to close, officials said Friday.

Helicopters swooped down to gather seawater and help battle the blaze at the Bovoni landfill on the island of St Thomas, which prompted US Virgin Islands Governor Albert Bryan to declare a state of emergency this week.

Puerto Rico’s National Guard said it supplied 60,000 gallons (227,000 liters) of water during its mission. Meanwhile, the US Virgin Islands National Guard dropped more than 11,000 gallons (41,600 litres) of water on the fire.

The Virgin Islands Daily News, a local newspaper, reported that the fire began spontaneously on September 14 in an area of mulched vegetation that was collected after hurricanes Irma and Maria struck the region in 2017.

Officials have told residents near the landfill to stay indoors, and have warned of possible water contamination.