SEATTLE (AP) _ Authorities set up a half-mile perimeter around a terminal at the city's port Wednesday after bomb-sniffing dogs indicated that two containers from Pakistan could contain explosives.

Dozens of personnel were evacuated from Terminal 18, south of downtown and nearby businesses were advised to keep their workers indoors. A bomb squad was examining the containers' contents.

U.S. Customs and Border Protection agents had used a ``gamma-ray'' device to peer through the containers' steel walls to determine what they contained and detected some of the items did not appear to match what was listed on the containers' manifest, said spokesman Mike Milne.

Officials said the containers were supposed to contain oily rags, which are often shipped internationally for recycling or use in packaging.

Bomb-sniffing dogs were used, per standard procedure, and agents also tested for hints of radiation, but detected none.

``The bomb-sniffing dogs did what bomb-sniffing dogs do, and it caused us to be worried there might be explosives,'' port spokesman David Schaefer said.

The Port of Seattle bomb squad used explosive charges to cut into the containers, which may have detonated any explosives therein, said spokesman Mick Shultz. Milne said the ship had originated in Hong Kong and made stops in China before arriving in Seattle on Monday.

Terminal 18 covers nearly 200 acres, making it the port's largest container terminal and one of the largest in the nation. It serves more than 20 steamship lines and receives more than 40 vessels each month.