Four more deaths from the coronavirus have been announced in the United States, bringing the total to 26.

Three more were announced in Washington state, which has borne the brunt of the deadly virus, with another in California.

The latest fatalities in Washington were all female residents of the Life Care Centre in Kirkland. All three are women, two in their 80s and one in her 70s. All but one of the 20 deaths in the state have been linked to the Life Care Centre.

In California a woman in her 60s who had been in hospital for several weeks succumbed to the virus in Santa Clara County. She had not travelled abroad recently and had had no known contact with anyone affected by the virus.

Sara Cody, the county health officer, said: "This is a tragic development.

"The Public Health Department is taking necessary, carefully considered steps to slow down the spread of the disease and to protect those at greatest risk. We are facing a historic public health challenge and know this is a very difficult time. Our top priority continues to be protecting the health of our community."

The deaths were announced as the Grand Princess cruise ship was finally allowed to dock in Oakland, California, after several days of being anchored off San Francisco.