HOUSTON (Reuters) – A fire at a fuels storage company at the Houston Ship Channel spread on Monday to eight massive petrochemical storage tanks, shutting schools and forcing residents in the suburb of Deer Park to stay indoors.

The fire, which sent a plume of black smoke across the city’s eastern half and was visible from 10 miles (16 km) away, began in a giant storage tank containing naphtha, a volatile component of gasoline, at about 10:30 a.m. on Sunday.

No evacuations or injuries were reported.

School officials in Deer Park, population 32,000, and nearby La Porte, Texas, with about 34,000 residents, suspended classes and told employees not to report to work on Monday.

Tanks containing naphtha and xylene, petrochemicals used to make gasoline and base oils commonly used as machine lubricants, were burning, officials of the Intercontinental Terminals Co (ITC) said.

The company said on Monday that a tank containing Toluene also caught fire. Toluene is used to manufacture nail polish remover and paint thinner.

The burning tanks are surrounded by several other storage tanks within a spill containment dike. Firefighters used a foam fire retardant on nearby tanks to try to limit the fire from spreading.

“ITC officials continue working with local first responders to contain the fire,” the company said in a statement. “The safety of our employees, the surrounding community and the environment is our first priority.”

Ships continued to cross the channel linking refineries and chemical plants in Houston and Texas City, with the Gulf of Mexico. The U.S. Coast Guard ordered ships not to dock at ITC or an adjoining terminal.

Air emissions tests detected the presence of a volatile organic compound six miles away from the facility. Levels were below those considered hazardous, ITC said.

The fire was not affecting operations at the nearby Royal Dutch Shell Plc joint-venture refinery in Deer Park, said Shell spokesman Ray Fisher.

(Reporting by Erwin Seba; Additional reporting by Rich McKay and Gary McWilliams; Editing by Emelia Sithole-Matarise and Jeffrey Benkoe)