An outbreak of coronavirus in a Portsmouth Naval Shipyard is being investigated by the Maine Center for Disease Control.

Nirav Shah said as of Thursday 18 new cases were confirmed among workers at the Portsmouth Naval Shipyard.

Some 13 of those individuals who tested positive for novel coronavirus are Maine residents, while four are from New Hampshire and one from Massachusetts, he said.

The Portsmouth Naval Shipyard (PNS), often called the Portsmouth Navy Yard, is a United States Navy shipyard located in Kittery on the southern boundary of Maine near the city of Portsmouth, N.H.

Maine's CDC director said Thursday it is the site of an outbreak of coronavirus where 18 confirmed cases have occurred. .

“One of the linkages that we have identified that may have generated this outbreak is a group of individuals who commuted together from Sanford to the Naval Shipyard,” Shah said.

“It is a common question we encounter whether an individual is incidentally someone who is detected or part of the outbreak we are seeing," Shah said.

The Maine CDC is working alongside the Navy Shipyard to investigate the outbreak and note the transmission patterns.