Increased patrols around mosques and other houses of worship in Los Angeles County remained in effect Tuesday a day after two teen shooters opened fire in a deadly attack at the Islamic Center of San Diego.

Three people were killed in the attack. The two suspected shooters, believed to be ages 17 and 19, also are dead from what authorities said were self-inflicted gunshot wounds.

Authorities in San Diego planned to provide an update on the investigation at noon.

The Los Angeles County Sheriff’s Department said Monday it was “actively assessing any potential threat to Los Angeles County” and had implemented increased patrol checks at critical facilities.

“Violence has no place in our society, and we remain committed to protecting our communities in Los Angeles County,” the department said in a statement posted on social media.

Police are investigating a deadly shooting at a mosque in San Diego. Eric Leonard reports for NBC4 at 4 p.m. on May 18, 2026.

The Los Angeles Police Department also announced increased patrols at mosques, Islamic centers and houses of worship throughout the city.

“Currently, there is no known threat to Los Angeles, but the LAPD remains vigilant,” the department said in a statement. “Out of an abundance of caution, we are providing extra patrols at mosques, Islamic centers and all houses of worship across the city to ensure our communities are safe and feel supported.”

Mayor Karen Bass said she was “outraged and heartbroken” by the shooting, noting that the attack occurred on the first day of Dhul Hijjah, a sacred period for Muslims.

“Houses of worship must be true sanctuaries where hate and violence have no place,” Bass said in a statement. “I stand firmly with the Muslim community and condemn this horrific attack.”

Bass said she had spoken with Muslim community leaders in Los Angeles and directed the LAPD to deploy additional resources to protect mosques across the city.

The Bureau of Alcohol, Tobacco, Firearms and Explosives said its Los Angeles Field Division was assisting state and local authorities with the investigation alongside the FBI and San Diego police.

The Los Angeles County Sheriff’s Department is aware of the active shooter at the Islamic Center of San Diego in the City of Clairemont. We are actively assessing any potential threat to Los Angeles County, and we have implemented increased patrol checks to critical facilities.… pic.twitter.com/70XB3XUQad

— LA County Sheriffs (@LASDHQ) May 18, 2026

Investigators are working to determine a motive, but San Diego’s police chief said the violence was being investigated as a possible hate crime.

Chief Scott Wahl said a security guard was among those killed during the attack in San Diego’s Clairemont neighborhood, about 8 miles north of downtown. He was among three men found dead in front of the mosque.

“At this point, I think it’s fair to say his actions were heroic,” Wahl said. “Undoubtedly, he saved lives today.”

All teachers, students and other school staff members who were at the mosque were safe. A landscaper who was working in the area was shot at but not struck, Wahl said.