Multiple people have been killed, three people officers were shot and a suspect is in custody following a shooting at a Pittsburgh synagogue Saturday.

Pennsylvania State Police tweeted an “actor is in custody.” The suspect was not immediately named.

The shooting was at the Tree of Life Synagogue in Pittsburgh’s Squirrel Hill neighborhood, which is about 10 minutes from downtown Pittsburgh and is predominantly Jewish.

Pittsburgh Department of Public Safety Public Information Officer Chris Togneri told Fox News in a statement that there was an active shooter but declined to make a comment “until the situation is resolved.”

KDKA reported people were barricaded inside the synagogue while residents were told to shelter in place in area.

Jeff Finklestein, the president and CEO of the Jewish Federation of Pittsburgh said he believed 60 to 100 people were in the synagogue at the time of the incident. It is unclear how many people were injured.

President Trump tweeted about the developing incident.

“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!” he wrote.

Pennsylvania Gov. Tom Wolf tweeted about the active shooting, calling it a “serious situation.” Wolf said he was on his way to the scene of the incident.

“We are still learning details about the shooting at the Tree of Life Synagogue in Pittsburgh but it is a serious situation. Pennsylvania State Police are assisting local first responders. Please stay away from the area and keep the congregants and law enforcement in your prayers,” he wrote.

He followed up his tweet with a lengthier statement which said: “The shooting in Pittsburgh this morning is an absolute tragedy. I have spoken with local leaders and my administration and the Pennsylvania State Police will provide any resources to assist local law enforcement and first responders.

“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.

“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.”

Pittsburgh City Councilman Corey O’Connor tweeted, “There is an active shooter near the Tree of Life in Squirrel Hill. Residents, please stay indoors. Our officers are on the scene. I will provide more updates once they are available.”

In response, both the NYPD and LAPD said they would be deploying extra teams to synagogues and Jewish locations throughout the cities.