A security guard at the Islamic Center in San Diego, California, has been hailed as a “hero” after he was killed while trying to prevent suspected shooters from entering the mosque complex in an attack police are investigating as a hate crime.

At least three people were killed after two teenage attackers opened fire at the San Diego mosque on Monday. Authorities have yet to publicly identify the victims, but community leaders have named the guard as Amin Abdullah.

United States officials said the guard “played a pivotal role” in preventing the attack from being “much worse”. “It’s fair to say his actions were heroic,” San Diego Police Chief Scott Wahl said at a news conference. “Undoubtedly, he saved lives today.”

At the time of the shooting, children were attending a private school located inside the complex, according to ABC News.

The suspected gunmen killed themselves a few blocks away.

So here’s what we know about the guard and the attack on the mosque complex.

Who was Amin Abdullah?

A family friend identified the guard as a well-known face at the mosque, who had been working there for more than a decade, The Associated Press news agency reported.

“He wanted to defend the innocent, so he decided to become a security guard,” said Sheikh Uthman Ibn Farooq, who had spoken with Abdullah’s son. The family could not immediately be reached for comment.

Local media reports suggest that Abdullah was a father of eight.

After Abdullah was identified by reports as one of the men killed in the attack, tributes started to pour in online. A Facebook profile associated with him has 1,800 followers and lists Abdullah as married.

His latest post was from May 13, featuring a video of a hawk perched upon the minaret of a mosque, captioned: “Hawk on the minaret again, Allahu Akbar.”

On May 5, he posted: “What is success? To many people success is financial stability, good reputation, beauty, etc. As for ME! Wallahi, thumma Wallahi. It is returning back to Allah OUR creator with the same pure soul he loaned me at birth.”

On the Facebook account, he had posted a few times each month since December 2025. His posts included reflections on Islam and videos of him practising archery.

Among the tributes for Abdullah were identical Facebook, X and Instagram posts by American Muslim scholar Omar Suleiman, who shared a screenshot of one of Abdullah’s Facebook posts.

In his caption, Suleiman wrote: “Brother Amin Abdullah was the guard at the mosque in San Diego for years. He was instrumental in stopping the shooters from reaching the children today. This was his final post on FB. On these holiest days, may Allah have mercy on him and accept him as a martyr. Ameen”

What happened at the San Diego mosque?

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

There was no specific threat made against the Islamic Center of San Diego, but authorities found evidence that the suspects engaged in “generalised hate rhetoric”, San Diego Police Chief Scott Wahl said. He declined to give more details, but said the “circumstances that led up to this” would come out in the days ahead.

Before the attack, officers were already looking for one of the teenagers since his mother called the police, concerned that her son was suicidal and had run away, Wahl said. There were weapons missing from the home, and the mother’s vehicle was gone, he added.

The search took on even more urgency as police learned that he was dressed in camouflage and with an acquaintance – details that were unexpected for someone about to die by suicide, he said.

Police began using whatever technology they could to find the 17- and 18-year-old, including automated licence plate readers. The department dispatched authorities to a mall near where the car had been tracked by police, and officers alerted a school where at least one of the suspects had been a student, Wahl said.

As officers continued interviewing the mother about places the teens might be, they got reports of a shooting at the mosque.

The centre is the largest mosque in San Diego County and includes the Al Rashid School, which offers courses in Arabic language, Islamic studies and the Quran for students ages 5 and up, according to its website.

Aerial TV footage showed more than a dozen children holding hands and being walked out of the car park of the centre as it was surrounded by dozens of police vehicles. The mosque is in a neighbourhood of homes, apartments and strip malls with Middle East restaurants and markets.

The Islamic Center’s website says its mission is to not only serve the Muslim population but also to “work with the larger community to serve the less fortunate, to educate, and to better our nation”. Five daily prayers are held there, and the mosque works with other organisations and people of all faiths on social causes.

What has been the response so far?

The mosque’s director, Imam Taha Hassane, called it “extremely outrageous to target a place of worship”.

“All the places of worship in our beautiful city should always be protected,” he said.

He added that the centre focused on interfaith relations and community building, and that a group of non-Muslims had been touring the mosque earlier Monday to learn about Islam.

The Council on American-Islamic Relations (CAIR), one of the largest Muslim civil rights and advocacy groups in the US, condemned the shooting.

“We are deeply disturbed, but not at all surprised, to learn that those who attacked the Islamic Center of San Diego were reportedly motivated by anti-Muslim hate,” CAIR said in a statement on Monday.

“Hate against American Muslims is completely out of control. Numerous politicians have spent the past year claiming that all ‘mainstream Muslims’ should be destroyed, that American mosques and elementary schools should be shut down, and that American Muslims should be expelled from our nation. Just last week, House Republicans held a congressional hearing to fan the flames of hate against American Muslims, their houses of worship and even Muslim schoolchildren.

“A deadly attack on an American mosque was as predictable as it is unacceptable. Anti-Muslim hatred is one of the last acceptable forms of bigotry in American society, and it is long past time for the tolerance of this hate to end.”

New York Mayor Zohran Mamdani said he was horrified by the attack. “I am horrified by the deadly attack at the Islamic Center of San Diego, an apparent act of anti-Muslim violence,” he posted on X.

“Islamophobia endangers Muslim communities across this country. We must confront it directly and stand together against the politics of fear and division. My thoughts are with the victims, their loved ones, and the entire community grieving this devastating attack.

“The NYPD [New York Police Department] is increasing deployments to mosques across the city out of an abundance of caution. There are currently no known threats to NYC houses of worship.”

US President Donald Trump called the shooting a “terrible situation”.