US shooting: 'End is coming, bombs all over', suspect warns cops, 4 killed

Four police officers were killed and seven others wounded by snipers in chaotic scenes in Dallas during a protest against police shootings of black men, with a suspect warning that bombs were planted throughout the city center.

City Police Chief David Brown said two snipers shot at "police officers from elevated positions during the protest/rally." A civilian was also wounded.

Police were continuing to exchange gunfire with a suspect holed up in a downtown garage hours after the shooting started.

The suspect "has told our negotiators that the end is coming, and he is going to hurt and kill more of us, meaning law enforcement. And that there are bombs all over the place in this garage and in downtown," Brown told reporters.

The gunfire broke out around 8:45 p.m. Thursday while hundreds of people were gathered to protest fatal police shootings this week in Baton Rouge, Louisiana, and suburban St. Paul, Minnesota.

The statement said three officers are deceased, two are in surgery and three are in critical condition.

"An intensive search" for suspects is currently underway, it said. No one is in custody.

Live TV video showed protesters marching along a street in downtown, about half a mile from City Hall, when the shots erupted and the crowd scattered, seeking cover.

Scores of police and security officers were on hand. Police and others hunched behind cars outside a parking garage. Officers with guns drawn were running near and into the parking garage as police searched for the shooter.

TV cameras showed the search for the gunman stretched throughout downtown, an area of hotels, restaurants, businesses and some residential apartments. The scene was chaotic, with helicopters hovering overhead and officers with automatic rifles on the street corners.