BOSTON, Feb 10 (Reuters) - An explosion at a New Hampshire ball bearing plant that could be felt up to a quarter-mile (400 meters) away on Monday injured up to 15 people, two critically, authorities said.
The explosion at the New Hampshire Ball Bearings Inc plant in Peterborough, about 75 miles (120 km) northwest of Boston, caused heavy damage and sent up a column of smoke, the Peterborough fire department said in a statement.
Ambulances transported about 10 to 15 people to hospitals, and two were critically injured, it said. Eight ambulances were sent to the site.
There was no known fire and the explosion is not believed to be an act of terrorism, the statement said. The cause is under investigation.
State and local officials had temporarily set up an emergency command center near the plant, a unit of Japan's Minebea Co Ltd.
Live images on New Hampshire's WMUR television showed emergency vehicles parked in front of the plant. The first-floor windows had been blown out by the blast, which occurred at about 3:30 p.m. EST (2030 GMT).
Reports have said the explosion was felt at businesses a quarter-mile (400 meters) away, the statement said.
Kathy Gerrity, assistant to the company's president, said in an email that the two critically hurt people were employees. About 700 people work at the plant, but she did not know how many were there at the time of the blast.
"We don't know yet when the facility will be back in operation," she said.