More than a hundred people were evacuated from Dole Cannery and the Dole Office Building in Iwilei yesterday after several explosions at a nearby vacant lot.

The explosions occurred about 1:30 p.m. at 616 Iwilei Road, forcing officials to evacuate the shopping center and office building because of the threat of another blast.

The initial blasts did not injure anyone, including the six or so employees at the site, said Honolulu fire Capt. Terry Seelig. No one else reported injuries.

Seelig said the first explosion was like a dust ball and was followed by two smaller explosions in the area. Officials closed the Dole complex for about two hours, reopening the buildings about 4:30 p.m. The Regal Cinemas movie theaters were not affected.

The blast at Pacific Street and Iwilei Road occurred as Weston Solutions Inc. worked on soil decontamination, Seelig said.

Seelig said the company injects the soil with chemicals such as peroxide. The chemicals react with waste products in the soil and produce a byproduct that is burnt off, leaving the soil decontaminated.

Fire investigators are trying to determine whether the explosion was caused by over-pressurization of gas in the reaction or ignited by a heat source, Seelig said.

Firefighters sprayed massive streams of water onto the site to cool the area so they could enter and confirm there was no longer a threat of further explosions.

State health spokeswoman Janet Okubo said Weston owns the site .

"In the process of cleaning up the site, something occurred," Okubo said.

Okubo said company officials were conducting an investigation.

The site was formerly used as part of a gas company refinery, she said.

"The site is very contaminated," Okubo said.

During the evacuation, employees stood outside the buildings, awaiting word on whether they could go back to work or would be sent home. About two hours later, the crowd had thinned to about a dozen.

Frances Kaina, general manager of Kakaako Bakery, was working across the street when she heard the first loud blast. "I looked out the window and it was a cloud of black smoke," she said.

Dave Kateley, promotions assistant for radio station 93.9 Jamz, was in the garage across the street when the explosion occurred and could see smoke, then a bright flame a few feet high coming from the ground. The flame grew higher and brighter, "like a tiki torch on steroids."

He said the evacuation came at a bad time, when he needed to work on promoting the new station.

"This is a major inconvenience," he said, but added, "I guess it’s better than being blown up."

Star-Advertiser reporter Gary T. Kubota contributed to this story.