A state senator whose district includes the area, Bill Dodd, earlier told reporters that the gunman was a member of Pathway Home, a program for veterans suffering from post-traumatic stress disorder, or PTSD, and that the hostages were believed to be employees of the facility.

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"This is a tragic piece of news we hoped not to share with the public," California Highway Patrol spokesman Chris Childs told reporters outside the sprawling facility in Yountville, a picturesque town located in the heart of Napa Valley's wine country about 60 miles (97 km) north of San Francisco.

The siege came less than a month after a former student with an assault-data-style rifle killed 17 people at a Florida high school. That massacre touched off a student-led drive for new restrictions on gun sales to curb mass shootings that have occurred with frightening frequency in the United States over the past few years.

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The Veterans Home of California, which houses about 1,000 disabled and aging military veterans, is the largest facility of its kind in the United States. The Pathway Home is housed in a separate building on the campus.

The entire complex, its staff and residents were placed under a security lockdown during the siege.

The gunman walked into the Pathway Home building carrying a rifle during a going-away party for one of the employees, according to Larry Kamer, the husband of one of the program's administrators who said he spoke to his wife by telephone during the standoff.

REUTERS