Two teenage gunmen opened fire at a mosque in San Diego on Monday, killing three men before later killing themselves, according to police.

Authorities said the attack at the Islamic Center of San Diego is being investigated as a possible hate crime.

San Diego Police Chief Scott Wahl told reporters that investigators are still working to determine what led to the shooting, adding that more details about the circumstances surrounding the attack are expected to emerge in the coming days.

The attack came the week before the Muslim holiday of Eid al-Adha, or Feast of the Sacrifice, and the annual Hajj pilgrimage to the holy site of Mecca in Saudi Arabia.

Here is what we know so far:

What happened at the San Diego mosque?

At about 9:42am local time (16:42 GMT) on Monday, police received a call from a mother reporting a “runaway juvenile”, Wahl said.

“The information that she was gathering and conveying to us began to elevate the threat level that we were perceiving,” Wahl added. “She believed her son was suicidal, and she began to share information that several of her weapons were missing, her vehicle was missing, in addition to her son.”

Roughly two hours later, at about 11:43am local time (18:43 GMT), officers responded to reports of an active shooter in the 7000 block of Eckstrom Avenue, arriving within about four minutes, authorities said.

Wahl said as many as 100 law enforcement officers entered the Islamic Center of San Diego after receiving reports of a possible shooting at the mosque.

When officers arrived, they found three people dead outside the building, prompting what Wahl described as an “active shooter response” inside the complex.

“They did have to breach doors to get into all of the different rooms,” Wahl told reporters at a news conference. “There was somewhere between 50 to 100 police officers inside of that facility.”

“No officers discharged their weapons,” Wahl added.

As police secured the area, gunfire erupted a few blocks away, where a landscaper was shot at but not injured, according to Wahl. The suspected attackers were later found dead inside a vehicle stopped on a nearby road.

Television aerial footage showed more than a dozen children holding hands as they were escorted from the mosque’s car park while the area was surrounded by police vehicles.

“I’ll tell you what got me,” Wahl said. “Watching kids come running out, just thankful to be alive.”

Officials said they are treating the shooting as a hate crime investigation unless evidence suggests otherwise.

Where did the shooting happen?

According to its website, the mosque is the largest in San Diego county, serving a congregation of more than 5,000 people.

The complex also houses Al Rashid School, which offers classes in Arabic, Islamic studies and the Quran for children aged five and older.

Located in a neighbourhood of homes, apartment buildings and strip malls with Middle Eastern restaurants and markets, the mosque describes its mission as serving the religious needs of San Diego’s Muslim community while also supporting and educating the wider public.

The centre says its activities include five daily prayers, Friday sermons, educational talks and community seminars, and that it welcomes visitors from all faiths.

Speaking soon after the shooting, Taha Hassane, an imam at the Islamic Center, condemned the attack.

“It is extremely outrageous to target a place of worship,” he said. “People come to the Islamic Center to pray, to celebrate, to learn – not only Muslims, but we have people from all walks of life.”

The Islamic Center is about 14km (9 miles) north of downtown San Diego.

What do we know about the attackers?

The two suspects found dead inside a vehicle were teenagers, authorities said. Wahl said they were 17 and 19 years old.

Authorities have released limited details about them.

Police said the mother who contacted authorities earlier in the day told investigators the pair were dressed in camouflage clothing and travelling together in a vehicle that had been reported missing.

“We also gathered information that one of the individuals was associated in some form or fashion with Madison High School,” Wahl said, adding that officers and school police increased security around the school’s campus during the investigation.

The mother also found a note, Wahl said. He did not disclose its contents but said of the case, “There was definitely hate rhetoric that was involved,” though there was no specific threat against the Islamic Center of San Diego, he added.

Authorities said the teenagers killed three people, including a security guard who worked at the mosque, before later killing themselves.

What do we know about the victims?

Among the deceased victims was a security guard who worked at the centre and “played a pivotal role” in preventing the attack from being “much worse”, officials said.

“It’s fair to say his actions were heroic,” Wahl said. “Undoubtedly, he saved lives today.”

Authorities have not yet publicly identified the three victims. But community leaders have identified the guard as Amin Abdullah. Local media reports suggested he was a father of eight.

What have been the reactions?

The Council on American-Islamic Relations condemned the shooting.

“No one should ever fear for their safety while attending prayers or studying at an elementary school,” said CAIR-San Diego Executive Director Tazheen Nizam in a statement. “We are working to learn more about this incident, and we encourage everyone to keep this community in your prayers.”

“Islamophobia endangers Muslim communities across this country,” Zohran Mamdani, New York City’s first Muslim mayor, said. “We must confront it directly and stand together against the politics of fear and division.”

California Governor Gavin Newsom released a statement that he was “horrified by today’s violent attack”, adding that “hate has no place in California.”

What is the state of Islamophobia in the US?

US civil rights advocates have for years warned about rising Islamophobia, linking it to the aftermath of the September 11, 2001 attacks, the so-called war on terror that followed, and more recently, to anti-immigration rhetoric, white supremacist movements and tensions surrounding Israel’s genocidal war on Gaza.

CAIR said it recorded 8,683 anti-Muslim and anti-Arab complaints in 2025, the highest number since the organisation began publishing data in 1996.

In a report, CAIR said many Muslims and people advocating for Palestinian rights increasingly felt targeted by government policies, political rhetoric and public suspicion.

“Government actions and official rhetoric treated Muslims, and people who speak up for Palestinian human rights, as suspicious and outside the circle of protected religious and civic life in 2025,” the report said.

A separate study published in April by the Center for the Study of Organized Hate found a sharp rise in anti-Muslim rhetoric from Republican elected officials since early 2025. Researchers cited more than 1,100 social media posts by Republican governors and members of Congress that the group classified as anti-Muslim bigotry.

Rights groups have also pointed to growing threats and attacks against mosques, Islamic schools and Muslim community centres across the US in recent years.

In February, shots were fired at the Pike County Islamic Center in Matamoras, Pennsylvania, during the holy month of Ramadan, damaging windows and furniture inside the mosque.

In October 2023, six-year-old Palestinian American boy Wadea Al-Fayoume was killed in Illinois after prosecutors said his landlord stabbed him and his mother in what authorities described as a hate crime linked to the war on Gaza.

Muslim elected officials have also repeatedly faced threats and harassment. Congresswoman Ilhan Omar, one of the first Muslim women elected to Congress, has frequently been targeted with death threats and anti-Muslim abuse.

What is the latest in the area?

Authorities said they have reduced the “Genasys advisory zone”, a geographically targeted public safety alert area, around the Islamic Center of San Diego as the investigation moves from the emergency response phase into what officials described as the “investigative phase”.

The restricted area has now been narrowed to Eckstrom Avenue, Cosmo Street, Balboa Avenue and Hathaway Street, according to officials, who continued to urge residents to avoid the area while investigators remain at the scene.

Police also encouraged residents to download the Genasys Protect app to receive emergency and public safety alerts directly for their area.