San Diego police reported that five individuals were shot at the Islamic Center of San Diego on Monday in an active shooter incident. Among those deceased were two suspected shooters and three victims.
Law enforcement officers converged on the Islamic Center of San Diego, the region's largest mosque, to confront reports of an active shooter at the complex, and police said the situation had been "contained."
The local NBC television affiliate, citing police sources, reported that "multiple people are down" inside the facility, then updated its report saying two suspects were killed.
Three victims shot dead at the Centre
Three victims have currently been confirmed dead by the police, including one security guard.
San Diego Mayor Todd Gloria first reported around noon PDT (1900 GMT) that he had been informed of an "active shooter situation" at the Islamic center in the Clairemont community of San Diego, California's second-most populous city.
The San Diego Police Department posted separately that its officers were on the scene "for a reported active shooter."
Footage from local television stations showed dozens of patrol cars on a highway bridge next to the Islamic Center, with police officers and their vehicles surrounding the grounds, aiming rifles at the facility.
TV images from the scene also showed armed officers making their way through the complex.
The Islamic Center in Clairemont is the largest mosque in San Diego County and houses the Bright Horizon Academy, a school providing Islamic education, according to its website.
"Emergency personnel are on scene and actively working to protect the community and secure the area," the mayor posted.
California Governor Gavin Newsom was briefed on the "evolving situation," according to his office of emergency services.
The San Diego Police Chief later announced that following initial investigations, they are treating the shooting as a hate crime.
This is a developing story.