Eleven people were killed in Saturday's shooting at the Tree of Life synagogue in Pittsburgh, according to Pittsburgh Public Safety Director Wendell Hissrich.
A city official had previously told CNN 10 people were killed.
"Today, the nightmare has hit home in the city of Pittsburgh," Hissrich said at a news conference Saturday afternoon.
Read MoreTen people were killed in a shooting Saturday morning at the Tree of Life synagogue in Pittsburgh, according to Curt Conrad, chief of staff for Pittsburgh City Councilman Corey O'Connor.
The suspect has been identified as Robert Bowers, 46, law enforcement officials told CNN.
The gunman made anti-Semitic statements during the shooting, a law enforcement official said.
Social media postings targeting Jews that are believed to have come from Bowers are a focus of the investigation, a federal law enforcement official told CNN.
Shortly before the shooting, in an account on the Gab social media platform that authorities are investigating, the suspect is believed to have posted he "can't sit by and watch my people get slaughtered. Screw your optics, I'm going in."
The Gab account has frequent anti-Semitic postings.
Four police officers were among six people wounded in the shooting, Pittsburgh Public Safety Director Wendell D. Hissrich said.
"It's a very horrific crime scene," Hissrich said at a brief news conference. "It's one of the worst I've seen."
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