Three men, one of whom was a security guard, were killed in a shooting at the Islamic Center of San Diego on Monday, authorities said, with investigators saying they are currently considering the incident as a hate crime.

Two suspects, aged 17 and 18, were reported dead from apparent self-inflicted gunshot wounds, police said.

Authorities are investigating two teenagers, Cain Clark and Caleb Vazquez, as the suspected attackers in the shooting, a number of sources told ABC News.

The shooting was reported shortly before noon Monday, police said.

Police are investigating a potential motive but said the shooting is currently being considered as a hate crime.

“There was definitely hate rhetoric that was involved,” San Diego Police Chief Scott Wahl said during a Monday press briefing.

Anti-Islamic writings were found in the vehicle with the two teens, sources told ABC News.

About two hours before the shooting at the mosque, San Diego police received a call involving one of the suspects, about a runaway juvenile, according to Wahl. The teen’s mother reported that “several of her weapons” and her vehicle were missing, he said. The mother also found a note, Wahl said, the contents of which the police chief did not share.

The mother told police that her son was with another individual and that they were both “dressed in camo,” Wahl said.

Officers were attempting to track down the vehicle and dispatched police to a mall and to a school with which one of the teens was associated, when the shooting at the mosque was reported, he said.

The Islamic Center of San Diego says it is the largest mosque in San Diego County.

“We have never experienced a tragedy like this before,” Taha Hassan, Imam and Director of Islamic Center of San Diego, said of the center at a news conference.

Hassan said he’s sending “prayers and standing in solidarity with all the families in our community here, and also the other mosques, and all the places of worship in our beautiful city.”

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

“The religious intolerance and the hate, unfortunately, that exists in our nation is unprecedented,” Hassan said.

“We strongly condemn this horrifying act of violence,” Tazheen Nizam, the executive director of the San Diego chapter of the Council on American-Islamic Relations, said in a statement. “Our thoughts are with everyone impacted by this attack. No one should ever fear for their safety while attending prayers or studying at an elementary school.”

San Diego Mayor Todd Gloria told ABC News that “we immediately have increased patrols around religious sites, both our Muslim, Jewish and other faith communities across the city. And I imagine we’ll maintain that posture for some time.”

“[I] believe that once the investigation is complete that that security guard will be credited with a tremendous saving of many, many lives, including many children, an absolute hero who sadly lost his life, but for whom we’re all grateful,” Gloria said.

“Hate has no home in San Diego. Islamophobia has no home in San Diego,” the mayor said during a press conference.

ABC News’ Meg Christie, Luke Barr, Mike Levine and Alex Stone contributed to this report.