BREAKING | Suspect in Cincinnati shooting dead

A gunman opened fire Thursday morning in a building in the heart of Cincinnati in an attack that left him and three other people dead, police said.

The shooting sent people scrambling across the city's Fountain Square amid cries of ``shooter!''

It happened at a 30-story building, home to the corporate headquarters for regional banker Fifth Third Bancorp and other businesses, including popular ice cream, pastry and sandwich shops.

The bank building was locked down for most of the morning, and surrounding streets and sidewalks were closed off.

Police Chief Eliot Isaac said the shooter opened fire at about 9:10 a.m. at the loading dock of the Fifth Third Bank building. Isaac said the gunman then entered the bank's lobby where he exchanged gunfire with police. It was unclear if the gunman shot himself or was shot by officers.

The gunman wasn't immediately identified, and police didn't comment on possible motive. Police later swarmed an apartment in North Bend, Ohio, a village some 15 miles west of Cincinnati. They didn't immediately explain the search.

``So, a very horrific situation,'' Isaac said at the shooting scene. ``We're in the very early stages'' of the investigation.

Federal and state agents were on the scene as police searched through the building.

One of the victims died at the scene.

Two more died at University of Cincinnati Medical Center. 

Cincinnati Mayor John Cranley said the gunman was ``actively shooting innocent victims.''

The Fountain Square often hosts concerts, dancing, food trucks and other events around lunchtime or in the evenings and is neighboured by a hotel, restaurants and retail shops.

``It could have been any one of us,'' Cranley said.

He praised ``the heroism'' of police who ended the threat within seconds and the response of other emergency personnel.