The Pacific Maritime Association (PMA) said in a tweet on Saturday that coordinated and disruptive work actions led by the International Longshore and Warehouse Union (ILWU) have shut down cargo operations at the Port of Seattle.

“On the first shift today, the ILWU refused to dispatch any longshore workers to container terminals, the PMA said, resulting in the shutdown of the port.

The Port of Seattle and ILWU did not immediately reply to a Reuters request for comment.

The PMA said there were work slowdowns in the second and third shifts on Friday directed by ILWU officials which brought ground operations at marine terminals to a halt and resulted in longshore workers being sent home.