One person was killed and four others were critically injured after a gunman opened fire on churchgoers near Los Angeles on Sunday.
Shortly before 1:30 p.m. (8:30 p.m. GMT), parishioners were attending a banquet following a morning service at Geneva Presbyterian Church when the gunman began his rampage, authorities said.
The churchgoers detained the shooter and "hogtied his legs with an extension cord and confiscated at least two weapons" before officers arrived at the scene to apprehend him, Orange County Undersheriff Jeff Hallock told a press conference.
"That group of churchgoers displayed what we believe is exceptional heroism, and bravery," Hallock said. "They undoubtedly prevented additional injuries and fatalities."
"One person is confirmed deceased at the scene," Hallock said. "Four others are critical and one other victim sustained minor injuries."
Officials said they were still sorting through the timeline and details with the approximately 30 to 40 witnesses who were inside the building in Laguna Woods, about 45 miles (70 kilometers) southeast of Los Angeles.
They were also waiting for help from a translator in interviewing members of the congregation and the alleged assailant, Hallock told reporters.
Investigators were still searching for a motive, he said, adding that the alleged gunman, who was not injured during the incident, was believed to be an Asian male in his 60s.
"The man is not believed to live in the area and investigators are working to determine his city of residence and whether he has any connections to the church or its congregants," the sheriff's department said in a statement.
The victims were mostly Asian and primarily of Taiwanese descent, the Los Angeles Times reported, citing authorities.
According to the sheriff's department, they were aged between 66 and 92.
The office of California Gov. Gavin Newsom said it was working with local officials to monitor the situation.
"No one should have to fear going to their place of worship. Our thoughts are with the victims," the office tweeted.
Democratic Congressperson Katie Porter, who represents Orange County in Washington, called the shooting "upsetting and disturbing news, especially less than a day after a mass shooting in Buffalo."
"This should not be our new normal."
The latest shooting comes one day after an 18-year-old white suspect shot dead 10 people and wounded three others – almost all of them black – at a grocery store in Buffalo, New York state, in what officials are calling a "racist" rampage.
Mass shootings have become shockingly common in the United States, where past efforts at tightening the nation's gun laws have generally fallen short in the face of the nation's powerful firearms lobby – even after horrific massacres.