(Adds fire spreading to more storage tanks)
HOUSTON, March 18 (Reuters) - A storage tank fire on the Houston Ship Channel on Sunday has spread to seven petrochemical storage tanks, forcing residents in the suburb of Deer Park, Texas, to stay indoors on Monday, but no evacuations or injuries were reported.
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. (1530 GMT) on Sunday.
By evening, it had engulfed a second tank containing xylene, a petrochemical that is also a component of gasoline, officials of the Intercontinental Terminals Co (ITC) said.
By early Monday morning, the fire had spread to five additional tanks, company officials said in a press release. Those tanks contained finished gasoline and base oil commonly used as machine lubricants, officials said.
"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."
The burning tanks are surrounded by several other storage tanks within a spill containment dike.
Ships continued to ply the channel linking refineries and chemical plants in Houston and Texas City, Texas, with the Gulf of Mexico, with the only curb an order from the U.S. Coast Guard not to dock at ITC or an adjoining terminal.
The fire was not affecting operations at the nearby Royal Dutch Shell Plc joint-venture refinery in Deer Park, said Shell spokesman Ray Fisher.
ITC was deploying fire-suppressing foam to control the fire, Vice President Alice Richardson said earlier.
"We're fighting this fire defensively to keep it contained to this tank," she told a news conference.
Reporting by Erwin Seba; Additional reporting by Rich McKay; Editing by Daniel Wallis/Clarence Fernandez and Emelia Sithole-Matarise