5 officers killed by snipers at protest

Snipers opened fire on police officers in the heart of Dallas, Texas, killing five officers and injuring seven others during protests in the United States over two recent fatal shootings by police of black men, police said.

Three people were in custody and a fourth suspect was killed by police using explosives after a long standoff in a downtown garage, police said.

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

Dallas Police Chief David Brown told reporters on Friday morning the snipers fired "ambush style" upon the officers.

Mayor Mike Rawlings said one member of the public was wounded by the gunfire.

Protests were also held in several other cities across the country on Thursday night after a Minnesota officer on Wednesday fatally shot Philando Castile while he was in a car with a woman and a child. The aftermath of the shooting was live streamed in a widely shared Facebook video.

A day earlier, Alton Sterling was shot in Louisiana after being pinned to the pavement by two officers. That, too, was captured on a cellphone video.

Video footage from the Dallas scene showed protesters marching along a street in downtown, about half a mile from City Hall, when the shots erupted and the crowd scattered.

Brown said that it appeared the shooters "planned to injure and kill as many officers as they could".

The search for the shooters stretched throughout downtown. The area is only a few blocks away from Dealey Plaza, where President John F. Kennedy was assassinated in 1963.

The scene was chaotic, with helicopters hovering overhead and officers with automatic rifles on street corners.

"Everyone just started running," Devante Odom, 21, told The Dallas Morning News.

Carlos Harris, who lives downtown, told the newspaper that the shooters "were strategic. It was tap, tap pause. Tap, tap pause".