This is a developing story. Last update: Noon, Oct. 28

(JTA) — The alleged gunman who killed 11 people and injured six at a Pittsburgh synagogue on Oct. 27 assailed the Jewish resettlement agency HIAS on his web page and said “I’m going in.”

The shooting occurred shortly before 10 a.m. during a bris circumcision ceremony at The Tree of Life, a 150-year-old Conservative movement congregation in the Squirrel Hill neighborhood, which has a substantial Jewish population. Some 100 worshippers were at the synagogue, which was holding three services at the time.

Police arrived on the scene just minutes after receiving calls about the gunfire and engaged the suspect, who has been identified as Robert Bowers, a 46-year-old white male. Bowers shouted “All these Jews need to die,” according to reports.

Among the injured were a 70-year-old male and a 61-year-old woman. The man had injuries to his torso and was in critical condition. Four police offers were wounded.

Pittsburgh Public Safety Director Wendell Hissrich called the attack a hate crime, which puts it under the purview of the FBI.

Bob Jones, the FBI official from the Pittsburgh office in charge of the bureau’s investigation, at a late afternoon news briefing called it the ‘most horrific crime scene” he has seen in his 22 years with the FBI.

Bowers surrendered to a SWAT team on the scene. He allegedly was carrying an assault-style rifle and multiple pistols, a law enforcement official said. The suspect was taken to a hospital, Hissrich said, but did not offer details.

On screen shots from his suspended web page on gab.com, Bowers wrote:

“HIAS likes to bring invaders in that kill our people.

I can’t sit by and watch my people get slaughtered.

Screw your optics, I’m going in,” he wrote.

The page also said that “jews are the children of satan. (john 8:44)”

Bowers’ account was rife with anti-Semitic conspiracies and anti-Trump posts/conspiracies.

Jason Lando, a police spokesman, told CNN that neighbors were told to keep indoors and shelter in place. Carnegie Mellon University also was put on lockdown.

Police said that at least three officers were hit in the gunfire exchanges.

President Donald Trump responded to the shooting on Twitter, saying that it “looks like multiple fatalities.”

“Watching the events unfolding in Pittsburgh, Pennsylvania,” Trump said. “Law enforcement on the scene. People in Squirrel Hill area should remain sheltered.”

Later Trump told reporters: “This is a case where if they had an armed guard inside, they might have been able to stop him immediately” and “maybe there would be nobody killed.”

Tree of Life, which merged five years ago with another congregation, Ohr L’Simcha, is on the same campus as two other synagogues: New Light, which is also Conservative, and Dor Hadash, a Reconstructionist synagogue.

The New York Police Department deployed extra officers to that city’s synagogues on Saturday morning.

Two of Pittsburgh’s professional sports teams, the Steelers and Penguins, were among those that tweeted their thoughts and prayers.

Here are the names of the victims of the Pittsburgh shooting

Joyce Feinberg, 75; Richard Gottfried, 65; Rose Mallinger, 97; Jerry Rabinowitz, 66; Cecil Rosenthal, 59; David Rosenthal, 54; Bernice Simon, 84; Sylvan Simon, 86; Daniel Stein, 71; Melvin Wax, 88; Irving Younger, 69

David and Cecil Rosenthal were brothers. Bernice and Sylvan Simon were husband and wife.