At least four people were killed and three officers injured responding to an active shooting incident in the area of a Pittsburgh synagogue on Saturday, local media and CNN reported.
"There are fatalities," an emergency responder said on local television station KDKA that was simulcast on CNN. The conditions of the officers were not immediately known.
One white male suspect was in custody, KDKA said, adding that responding officers "received fire."
Earlier, a police commander said the shooting resulted in "multiple casualties." Police surrounded the Tree of Life synagogue after reports of an active shooter at the building in the city`s Squirrel Hill neighborhood, local TV news images showed.
"Do not come out of your home right now, it is not safe," Pittsburgh police Commander Jason Lando warned local residents, in an impromptu news conference at the scene.
The Pittsburgh Public Safety Department had said on Twitter that there was an active shooter in the area of the location of the synagogue.
Local TV news footage showed police at that location with rifles and wearing helmets and other tactical gear. Paramedics also were stationed near the synagogue and police vehicles were blocking some streets in the area.
US President Donald Trump said in a tweet he was watching developments in a shooting incident on Saturday morning in Pittsburgh where it looked like there were "multiple fatalities."
The Tree of Life synagogue describes itself on its website as a conservative congregation that is traditional, progressive and egalitarian.