Residents of two towns were ordered to stop using water from their taps after someone broke into the area's supply facility and left behind a 5-gallon container that had an odor.

Authorities have ruled out terrorism, and the FBI has decided not to pursue the case, Dr. David Gifford, director of the Rhode Island Health Department, said Tuesday at a news conference.

The ban remained in effect while the container and water were being tested for biological or chemical contaminants, he said. Results were not expected until Wednesday at the earliest.

The system serves nearly 9,000 residents in Blackstone and about four dozen homes in neighboring North Smithfield, R.I. There have been no reports of illness.

Officials said someone cut barbed wire to enter the facility late Monday, cut the lines to an alarm, and then damaged an electrical panel and a vent at the top of a 1.3-million-gallon storage tank.

The 5-gallon container was found on top of the storage tank, said Ed Coletta, a spokesman for the Massachusetts Department of Environmental Protection.

Blackstone police said there were reports Monday night of teenagers fleeing the scene.

North Smithfield Town Administrator Robert Lowe said Tuesday that the sophistication of the break-in unnerved him.

The Massachusetts DEP said in a statement that "until further notice, residents should not ingest or have the water contact their skin, and should not wash clothes or dishes; flushing of toilets is permissible.

The Rhode Island Health Department issued similar precautions. They probably would remain in effect overnight, said Maria Wah-Fitta, a department spokeswoman.

Blackstone schools were expected to be closed Wednesday. On Tuesday school officials locked down the bathrooms, rented portable toilets and provided bottled water, juice and milk for students, said Kathleen Montagano, assistant superintendent of the Blackstone-Millville district.

North Smithfield residents were asked to turn on their faucets for at least 10 minutes Tuesday to help flush the water system, Lowe said.

Residents — and stores — were stocking up on bottled water. Some businesses, such as coin-operated laundries and restaurants, closed for the day.

Charlene Gignac, a clerk at a convenience store that ordered five times its regular amount of water for Wednesday, said she had already taken a shower Tuesday before she heard about the break-in.

"I'm wondering, 'OK, how bad is it?"' she said. "But I still have a pulse and I'm still kicking."

The two towns are about 55 miles south of Boston.