SAN DIEGO: Two teenage gunmen opened fire at a mosque in San Diego on Monday, killing three men before taking their own lives a few blocks away, police said.

The attack at the Islamic Center of San Diego is being investigated as a hate crime, according to San Diego Police Chief Scott Wahl.

Police said officers had earlier spoken with one of the teenagers’ mother after she reported around 9:40 a.m. that her son was missing along with multiple weapons and her vehicle.

Wahl said the mother had also found a note containing hate rhetoric, though there was no specific threat against the mosque.

One of the teenagers was identified as a student at Madison High School, located about a mile from the mosque. Authorities have not released the names of the shooters.

Among the dead was a mosque security guard, whom police said played a key role in preventing the attack from becoming “much worse.”