A shooting at a synagogue in Pittsburgh, U.S. state of Pennsylvania, on Saturday caused "multiple casualties," local authorities said.
Three officers were shot at the Tree of Life Congregation in Pittsburgh's Squirrel Hill neighborhood.
The gunman, a heavy-set white male with a beard, surrendered and is in custody, police said.
Local CBS affiliate KDKA reported that eight people were killed and identified the gunman as Robert Bowers.
CNN said at least 12 people have been shot, citing a law enforcement official.
A spokesman for the Pittsburgh Police Department said officers were still carrying out searches at the synagogue in the city's eastern Squirrel Hill neighborhood.
The synagogue is located at the intersection of Wilkins and Shady avenues. The neighborhood of Squirrel Hill, about 10 minutes from downtown Pittsburgh, is the hub of the city's Jewish community.
The synagogue offers members a "traditional Conservative service with a modern sense of family" and shabbat service on 9:45 a.m. Saturdays, according to the Tree of Life's website.
Carengie Mellon University, a college near the synagogue, is on lockdown.
"Police operations are ongoing. Avoid the Squirrel Hill/Shadyside area," the university's police tweeted.
U.S. President Donald Trump said he was watching the incident.
"Looks like multiple fatalities. Beware of active shooter," the president tweeted.
Pennsylvania Governor Tom Wolf tweeted that the situation is "serious" and encouraged citizens to stay away from the area.