BLACKSTONE, Mass. -- Police arrested three teenagers Wednesday in connection with a break-in at the Blackstone water supply.

Authorities said two 15-year old boys were facing charges of tampering with a water supply and malicious destruction of property, both felonies, as well as trespassing, a misdemeanor. A 15-year-old girl was also facing a trespassing charge. All three were to appear in Worcester Juvenile Court Wednesday.

Meanwhile, Blackstone-Millville schools remained closed Wednesday as officials in that town awaited the results of water testing after officials discovered the break-in at the town's water storage facility.

Authorities said the break-in Monday night was not an act of terrorism, but they weren't taking any chances.

NewsCenter 5's Gail Huff reported that the water ban, affecting some 9,000 residents in Blackstone and dozens of homes in North Smithfield, R.I., was to remain in effect until at least noon Wednesday, but officials have interrogated several people in connection with the case.

Officials said the break-in was fairly sophisticated, with the vandals cutting through barbed wires and an alarm system to get into the facility.

"There was a large steel door that was pried open. The doorknob was taken off the door," Town Administrator Raymond Houle said.

The vandals left behind a 5-gallon container with a strange odor and a dried-out substance inside. It was sent for testing and a water ban was put into effect. Residents were told they should not drink, cook or bathe with the water. Some businesses, such as restaurants and laundromats were closed. Bottled water was being trucked in and distributed from the fire station. Each resident was being given one gallon.

"We can't wash up. We have a little baby in the house and we need a jug here to wash the baby. It's pretty hard. I mean, you can't wash your hands. You keep forgetting and you go to wash your hands or cook and you can't. It's tough," resident Michelina LaChapalle said.

The state was testing the substance found in the bucket and the water supply in general and was hoping to have some results by Wednesday morning. The towns of Blackstone and Smithfield are about 55 miles southwest of Boston.