Maryland Gov. Larry Hogan (R) said Thursday that state officials had confirmed the first case of community spread of the coronavirus, warning that further transmission in communities immediately adjacent to the nation's capital were inevitable.

At a press conference in Annapolis, Hogan said health officials had identified a case in Prince George's County in a man who had not traveled out of state.

Hogan raised the state's emergency activation system to its highest level, activating the National Guard in an effort to battle the virus. He signed an order prohibiting gatherings and events of more than 250 people, and an order closing the cruise ship terminal at the Port of Baltimore.

Karen Salmon, Maryland's Superintendent of Schools, said that all public schools in the state would be closed for two weeks beginning on Monday.

Hogan also said visits to state prisons have been suspended, and hospitals across the state had been ordered to implement policies meant to limit visitors. State employees who are capable of working from home were ordered to do so.

Hogan said he would delegate the day-to-day operation of state government to Lt. Gov. Boyd Rutherford (R) so that Hogan himself can focus on the fight against the virus full-time.

Maryland has confirmed 12 cases of COVID-19, two of whom remain in hospitalized care, state officials said. Three of those 12 cases have recovered and made it through a quarantine period.

Hogan, the chairman of the National Governors Association, had been scheduled to give a State of the States address Thursday in Washington. He canceled that speech early Thursday in order to be back in Annapolis.

Maryland is one of 30 states and the District of Columbia that have issued emergency declarations.