Two teenagers accused of carrying out a deadly attack at a mosque in San Diego were allegedly radicalized online, where investigators say they first connected and shared extremist white supremacist beliefs.

According to the FBI, the suspects — ages 17 and 18 — expressed hatred toward multiple groups, including Muslims, Jewish people, Black people, the LGBTQ+ community, women, and individuals across the political spectrum. Authorities said writings recovered during the investigation revealed violent rhetoric and extremist ideology centered on white supremacist beliefs.

Investigators said the two teens died by suicide after killing three people during Monday’s attack at the Islamic Center of San Diego. They were later discovered inside a nearby vehicle. Authorities also recovered firearms, ammunition, and a crossbow during searches conducted at two residences connected to the suspects.

FBI officials said the pair met online before realizing they both lived in the San Diego area. Investigators are continuing to examine how the suspects became radicalized and whether they had additional plans beyond the mosque attack.

The writings obtained by investigators allegedly referenced white nationalist conspiracy theories claiming white people were being “eliminated.” One of the suspects also wrote about struggles with mental health and feelings of rejection. The documents reportedly included Nazi-related imagery and references to the Christchurch mosque shooter responsible for the 2019 terrorist attack in New Zealand that killed 51 people.

Community leaders and officials praised the actions of mosque security guard Amin Abdullah, who was among those killed. Religious leaders said Abdullah confronted the attackers and helped initiate a lockdown that protected approximately 140 children inside nearby classrooms.

Police said Abdullah exchanged gunfire with the suspects as they attempted to force their way into the mosque. Authorities believe his actions prevented even greater loss of life.

The other victims were identified as Mansour Kaziha and Nader Awad, both described by community members as deeply involved in the mosque and widely respected within the local Muslim community.

The attack comes amid heightened concerns over rising hate crimes and threats targeting religious communities in the United States, particularly Muslim and Jewish organizations following ongoing tensions related to conflicts in the Middle East.

Authorities said the investigation remains ongoing as federal and local agencies continue reviewing digital evidence, online activity, and communications linked to the suspects.