ANCHORAGE, Alaska (AP) — A seafood processing plant in Anchorage has found 56 employees tested positive for COVID-19, marking the latest outbreak in the industry, health officials said.

The Anchorage Health Department announced Friday that testing was conducted between July 17 and July 22, and more workers could test positive as 30 test results are still pending.

The plant is owned by Copper River Seafoods and employs 134 workers, many who live in the city.

“This is a concerning situation for the people of Anchorage,” said Bruce Chandler, disease control and prevention medical officer with the city health department. “With so many workers now testing positive, it is likely that this outbreak has been in progress for some time and that transmission has already occurred among family, friends and others in the community.”

The city and state health departments have started contact tracing and employees at the plant are being isolated in compliance with guidelines from the Centers for Disease Control and Prevention, officials said.

The two agencies have also coordinated with Copper River Seafoods to prevent further spread of the virus. Copper River Seafoods closed the plant after the first case was identified and is cleaning the facility.

For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. But for some — especially older adults and people with existing health problems — it can cause more severe illness, including pneumonia and death.

The confirmed cases at the Copper River Seafoods plant mark the third-largest outbreak in the Alaska industry, the Anchorage Daily News reported. The outbreak was reported a couple days after an OBI Seafoods processing plant in Seward saw about 100 confirmed cases among workers.