NEWARK, N.J. (AP) — Authorities have narrowed their search for suspected stowaways aboard a cargo ship in New Jersey.

Coast Guard spokesman Charles Rowe tells The Associated Press on Wednesday that authorities have inspected 80 of the 200 containers that authorities believe could be carrying people. The ship has 2,000 containers altogether.

Rowe says a Coast Guard team conducting a routine inspection heard knocking inside a container as the vessel approached New York Harbor early Wednesday.

Emergency vehicles are standing by near the ship, while others that were on the pier earlier have left.

The container’s manifest said it was carrying machine parts to Norfolk, Va.

The ship began its voyage May 30 in the United Arab Emirates. Its last port before Newark was in Egypt on June 15.