"For clarification, no church services were being conducted at the time of the stabbing," San Jose Police said in a statement. "Unhoused individuals were brought into the church to get them out of the cold."
The Grace Baptist Church is known for being a safe haven for the homeless community, according to a report from CBS SF Bay Area.
Police earlier reported there were "multiple stab victims; some with life-threatening injuries".
A suspect has not yet been taken into custody.
"Thank you to (San Jose Fire Department) and our first responding officers who rendered aid to victims in the middle of a chaotic scene and undoubtedly saved lives," San Jose Police said.
Video from the scene showed a large police presence, as well as a number of ambulances at the scene.
The church is on E San Fernando St near the San Jose State University campus.