A SWAT police officer and other first responders respond after a gunman opened fire at the Tree of Life synagogue in Pittsburgh, Pennsylvania, U.S., October 27, 2018. Photo: REUTERS/John Altdorfer.

Eleven people were killed in a mass shooting at a synagogue in Pittsburgh on Saturday morning.

According to the local CBS affiliate KDKA, a man described as a “heavy-set white male” named Robert Bowers opened fire at the Tree of Life Synagogue in the heavily Jewish neighborhood of Squirrel Hill.

Large numbers of congregants were present at the synagogue for Shabbat services. At least eleven victims have been confirmed dead, though how many were synagogue attendees has not been confirmed.

Former Tree of Life president Michael Eisenberg told KDKA, “At 9:45 there were three simultaneous congregations’ services that were being held. In the main part of the building, The Tree of Life has a service that has about 40 people in it. Just below that there is a basement area where New Life congregation would have been having their Shabbat service. There would have been 30-40 people. Just adjacent to Tree of Light’s service area, a congregation was in the rabbi study room and they would have had approximately 15 people in there.”

After the shooter opened fire, congregants reportedly barricaded themselves inside the synagogue. Police and a SWAT team arrived and exchanged fire with the attacker. Three policemen were apparently wounded and there is no word on their condition.

The shooter, who was also wounded, reportedly shouted “all Jews must die” before opening fire. He eventually surrendered to police.

President Donald Trump reacted quickly to the news, tweeting, “Watching the events unfolding in Pittsburgh, Pennsylvania. Law enforcement on the scene. People in Squirrel Hill area should remain sheltered. Looks like multiple fatalities. Beware of active shooter. God Bless All!”

Watching the events unfolding in Pittsburgh, Pennsylvania. Law enforcement on the scene. People in Squirrel Hill area should remain sheltered. Looks like multiple fatalities. Beware of active shooter. God Bless All!

— Donald J. Trump (@realDonaldTrump) October 27, 2018

Pennsylvania Governor Tom Wolf issued a statement following the attack, saying, “The shooting in Pittsburgh this morning is an absolute tragedy.”

“These senseless acts of violence are not who we are as Americans. My thoughts right now are focused on the victims, their families and making sure law enforcement has every resource they need,” he added.

He appeared to connect the shooting to the issue of gun control, stating, “We must all pray and hope for no more loss of life. But we have been saying ‘this one is too many’ for far too long. Dangerous weapons are putting our citizens in harm’s way.”

“And in the aftermath of this tragedy, we must come together and take action to prevent these tragedies in the future. We cannot accept this violence as normal,” he concluded.