SEOUL, South Korea — South Korea says it’s testing 176 workers at the southern port of Busan following a coronavirus outbreak among crew members of a Russian cargo ship that has so far sickened 16.

Kwon Jun-wook, director of South Korea’s National Institute of Health, said Tuesday that all 21 crew members were tested after the ship arrived at Busan’s Gamcheon Port on Sunday carrying frozen seafood.

He said the ship’s captain failed to properly inform port authorities that three of the crewmembers had high fever. The 176 people being tested included cargo handlers, customs officials, repair workers and interpreters who made contact with the infected crew members. Port officials and workers earlier on Tuesday agreed to halt unloading cargo from the ship and another Russian ship at the port.

South Korea reported 46 new cases of COVID-19 on Tuesday, including 30 linked to international arrivals. The country has been struggling to stem a resurgence of the virus in the Seoul metropolitan area, where hundreds of infections have been linked to entertainment and leisure activities, church gatherings and sales and warehouse jobs.