Five people, including two suspected shooters, killed at San Diego Islamic Center

US police have responded to a shooting at a mosque in California, with officials saying the threat had been ‘neutralised.’

The area around the Islamic Centre of San Diego was locked down, after witnesses said they heard dozens of shots fired. pic.twitter.com/5T44LULrCL

Wahl, speaking at a news conference after authorities had earlier declared the threat had been "neutralised," said one of the deceased was a security guard who worked at the centre.

"Because of the Islamic centre location, we are considering this a hate crime until it's not, and at this point we're going to work closely with the FBI to make sure that we are matching all the resources that we need for this investigation," he added.

All of the children attending a day school at the mosque complex were accounted for and safe after the shooting, which erupted at about 11:40am PDT (11:40pm PKT), police officials and Wahl said.

Earlier on Monday, authorities had said officers were responding to reports of an active shooter incident at the centre, located in the Clairemont neighbourhood near the 7,000 block of Eckstrom Avenue.

President Donald Trump described the shooting incident as a “terrible situation".

“They're giving a briefing on it ...and it's a terrible situation. I've been given some early updates, but we're going to be going back and looking at it very strongly," Trump told reporters at the White House.

'Extremely outrageous' to target place of worship

The mayor of the US city of San Diego sharply rebuked Islamophobia on Monday after two gunmen opened fire at a local mosque, killing three people.

"Hate has no home in San Diego. Islamophobia has no home in San Diego. An attack on any San Diegan is an attack on all San Diegans, and we will not stand for it," Todd Gloria told reporters at a press conference hours after the fatal shooting.

"Let there be no misunderstanding for anyone who would seek to bring this kind of violence to this city: you will be met with the full force of our law enforcement partnerships. Anyone who seeks to harm here will understand the response will be swift, and you will be brought to justice," he added.

Three people, including a security guard, were fatally shot at the Islamic Centre of San Diego on Monday.

San Diego Police Department Chief Scott Wahl said that as officers were responding to the scene, police received calls of another shooting nearby and found a landscaper who may have been shot in a helmet he was wearing, "that deflected and saved his life".

"A couple blocks away from there, we also received a call where a community member reported our two suspects in a vehicle, and it appeared they had gunshot wounds, and upon our arrival, we determined they were deceased," he said.

Law enforcement officials earlier said the suspects died from self-inflicted gunshot wounds.

The suspects' identities have not been released, but Wahl said one of the suspects’ mothers had called police Monday morning to report her child as a runaway who she believed to be suicidal. Additional information provided by the mother "led us to believe that there was a bigger threat picture here that we needed to consider," said Wahl.

That included information from the mother, who said her son took three weapons from her, as well as a note she discovered, Wahl said. Authorities declined to specify what kind of information was contained in the note, but Wahl said they have found evidence of what he described as a "general hate kind of speech that I think covered a wide gamut".

"I don't want to go into any of the specifics at this point. Again, we are still actively investigating this as we speak, but it was more generalised," he said.

CNN reported that multiple law enforcement officials said the "suicide note" contained "writings about racial pride" and that there was "hate speech" written on one of the weapons that were used.

Wahl maintained "there was no specific threat, especially no specific threat to the Islamic Centre".

Imam Taha Hassane, who leads the Islamic Centre of San Diego, made an impassioned appeal for the country to rise above what he described as "unprecedented" hatred.

"My community is mourning. This is something that we have never expected to take place, but at the same time, the religious intolerance and the hate, unfortunately, that exists in our nation, is unprecedented," he said.

"All of us, we are responsible for spreading the culture of tolerance, the culture of love. All of us, we are responsible from whatever position we have, as parents, as media people, as elected officials, as law enforcement, as religious leaders. All of us can do something to protect our nation, to protect our society," he added.

Erbil Atay, a resident, told Anadolu that he was supposed to meet with the mosque’s imam on Monday but was running late. If that were not the case, he said, “I would have most likely been present during the incident as well. We would have done whatever we could. But, as it happened, it was not to be".

Atay, who has lived in San Diego for 30 years and runs a paint business, said there had been no specific threats directed at the school or the Islamic Centre, but said there was a rock-throwing incident roughly a decade ago.

“Bulletproof windows had previously been installed on the wall in the school courtyard. But there was no specific threat,” he said.

The Council on American-Islamic Relations (CAIR) in San Diego had also released a statement after the incident, saying initially that at least one person had been killed.

To God we belong, and to God we return. We have learned from @CAIRSanDiego that at least one person was killed by a shooter at the Islamic Center of San Diego today. May Allah grant him the highest rank of Paradise and protect everyone from harm.

No one should ever fear for…

"May Allah grant him the highest rank of Paradise and protect everyone from harm. No one should ever fear for their safety while attending prayers or studying at an elementary school," CAIR said on the US social media platform X.