Police search of U-Haul truck outside Okla. City building turns up empty, report says

Bomb-sniffing dogs investigate a U-Haul truck discovered outside City Hall in Oklahoma City on April 17, 2013.

(CBS/AP) OKLAHOMA CITY - Oklahoma City police ordered the evacuation of City Hall and nearby buildings Wednesday morning after a U-Haul truck was discovered outside the building.

According to CBS affiliate KWTV, the Oklahoma City Police bomb squad later searched the truck and found it was empty.

Police Capt. Dexter Nelson said a five- to six-block area was cordoned off during the investigation.

Nelson said the evacuations were ordered as a precaution and that there was no evidence that suggested there might be a bomb in the truck.

The investigation began because police initially believed the truck had been stolen and they could not locate the driver, KWTV reports. It was later learned that the truck had reportedly broken down.

Nelson said Oklahoma has always been a "hyper-vigilant" state after the Oklahoma City bombing, and that Monday's bombings at the Boston Marathon gave even more reason for caution.

On April 19, 1995, Timothy McVeigh detonated explosives packed into a yellow Ryder rental truck, killing 168 people in and near the Oklahoma City federal building. This Friday will mark the 18th anniversary of that bombing.