PHOENIX (Reuters) - Seven workers at an Intel Corp microchip manufacturing plant outside Phoenix were injured by an explosion at the facility on Tuesday, and the building was immediately evacuated, fire officials said.
The blast of undetermined origin occurred shortly after 2 p.m. local time at one of two large Intel campuses in Chandler, Arizona, just southeast of the state capital, said Chandler Fire Department Battalion Chief Brad Miller.
He told Reuters that four workers were taken to local hospitals with injuries ranging from concussions to shrapnel wounds, and three others were treated at the scene for less serious injuries.
The extent of damage from the blast was not immediately clear.
The plant, which Miller described as a fabrication facility for microchips, was evacuated of several hundred workers after the blast and will remain closed indefinitely as authorities investigate the cause.
"Until we identify everything involved, there's no way we can say when people will be back to work," he said, adding that other buildings on the campus remained open.
Intel's website said its fabrication facilities in Arizona manufacture the company's Pentium processor family of products.
(Reporting by David Schwartz; Writing by Steve Gorman; Editing by Greg McCune)