BERKELEY HEIGHTS, N.J. (AP) _ Crews safely removed seven chemical-filled containers near a flaming and potentially explosive canister in the ruins of a burned chemical plant Saturday, clearing the way for nearly 1,500 evacuees to return home.

The burning, gas-filled container was found Friday in the Gollob Analytical Services chemical plant, where an explosion and fire killed three men Thursday and severely injured a fourth. A canister that had been sent to the plant for analysis caused the explosion, and authorities say it may have been mislabeled or contaminated.

In Pocatello, Idaho, meanwhile, a semiconductor plant that may contain a similar canister was also evacuated Saturday, as was a nearby nursing home.

New Jersey authorities, fearing that the burning container that was discovered Friday might ignite surrounding ones, called for a half-mile evacuation around the ruined plant Friday night.

Once the chemical containers near the one that was burning were removed, the cordon was reduced to one-quarter mile at 6 p.m. Saturday, allowing most of the 1,500 affected residents to return home, said Mayor Jeffrey Maccarelli. The remaining canister continued to burn Saturday evening but appeared to pose no hazard, he said.

Neil Mulvey, coordinator for the state Department of Environmental Protection, said Thursday's explosion had obliterated the lettering on at least one of the surrounding canisters, which hampered their removal.

Investigators said the plant burst into flames Thursday after a cylinder exploded outside the facility and became a projectile, shooting into the building.

DEP spokesman Jim Staples said the canister that exploded had a potent combination of 70 percent silane and 30 percent nitrous oxide. Minutes before it blew up, Gollob officials had called Liquid Carbonic Industries Corp., a Chicago-based chemical distributor that had manufactured the compound, to come and remove it.

After the explosion, Liquid Carbonic alerted the Gould Semiconductor Plant in Pocatello, Idaho, that similar canisters might be stored there.

Pocatello police Lt. Steve Stuart said he was told the cylinder that exploded in New Jersey had been shipped there from Idaho after it failed to work properly when being used in manufacturing at the Pocatello plant.

Dan Schroeder, Gould's plant manager, would not comment except to confirm sandbagging and an evacuation of a nearby nursing home were going on Saturday. ''There is very little jeopardy of a major disaster happening,'' he said.

In addition to the plant and a nursing home, the Idaho State University Research Park complex and a junior high school where a sports function was being held also were evacuated. The nursing home housed 91 persons, authorities said.

Plant officials had placed 2,800 sandbags around a suspect canister, and a hazardous materials expert from Carbondale, Colo., was at the plant evaluating the situation.