Confirmed U.S. deaths from COVID-19 increased Monday to six, all of them in Washington state.

The toll includes four new deaths announced by Seattle area officials Monday.

"We now know that the virus is actively spreading in some communities," said Washington State Health Officer, Dr. Kathy Lofy at a press conference. 

Lofy said Washington state has at least 18 confirmed cases and 29 pending test results.

14 of those confirmed cases are in the same area as a nursing facility authorities believe might be a hub for the virus.

Several additional employees and residents are being tested.  

More cases have been confirmed in other states, according to the U.S. Centers for Disease Control. 

The federal agency's official count now totals 91, including "presumptive positive" cases for patients who have tested positive at a state or local lab.

At least 48 of these cases involve people who traveled from Wuhan, China, or were aboard the Diamond Princess cruise ship; 17 cases are travel-related and 26 are the result of human-to-human interaction, according to the CDC.

Coronavirus infections are now reported in ten states in all: Washington, Oregon, California, Arizona, Wisconsin, Illinois, New York, Massachusetts, Rhode Island and Florida.