Honolulu police blew up a suspicious-looking backpack that forced the closure of Ward Avenue in both directions for about two hours yesterday.

Police got a call from security at Hawaiian Electric Co. at 2:36 p.m. and began closing the road between Kapiolani Boulevard and King Street about 3:30 p.m.

HECO spokesman Peter Rosegg said the backpack was found near the base of the flagpoles, fronting HECO’s building on Ward Avenue.

Security called police because the backpack appeared suspicious, and police took over. Employees were not evacuated, although a few parked nearby were asked to move their vehicles, he said.

HECO deferred further comment to the police.

The Police Department’s bomb unit with the Specialized Services Division deployed a remote-controlled robot to inspect the backpack.

After about 40 minutes, the wheeled robot left HECO’s property and rolled across the street. Police retrieved the robot and sent it back.

Soon after, an explosion could be heard.

Police reopened Ward Avenue about 5:50 p.m.

Police said the backpack was exploded in place. An officer took away two brown paper bags containing the remains of the backpack, which police would not describe, citing the ongoing investigation.

A detective with the Criminal Intelligence Unit was also at the scene.

Police classified the event as a miscellaneous incident but could reclassify the case, pending further information.

"We don’t even know if there was any criminal act involved," said an officer who responded to the scene. "It could have been some innocent person who left the bag there."