Five police officers have been shot dead by at least two snipers at a protest in Dallas, Texas.

Brent Thompson

Patrick Zamarripa

 

Six other officers have been wounded in the attack along with at least one civilian.

 

President Barack Obama has described the attack as “a vicious, calculated and despicable act” and vowed those responsible would be held accountable.

 

Two of those killed have been named as 43-year-old Brent Thompson of the Dallas Area Rapid Transit police department, and Patrick Zamarripa.

 

One of the gunmen, who had been involved in an stand-off with police and exchanged fire with officers from inside a parking garage, is reported by local media to have killed himself.

 

He had told officers that “the end is coming”, that he intended to kill more police, and that there are bombs “all over downtown Dallas”.

 

Police have said “extensive sweeps” are being carried out for explosives.

 

Three suspects, thought to be two men and a woman, are in custody. Two of them were stopped in a black Mercedes car following a high speed chase. 

 

The initial gunshots were heard at Belo Garden Park around 8.45pm local time, as hundreds of people gathered to protest over fatal police shootings this week in Baton Rouge, Louisiana, and suburban St Paul, Minnesota.

 

Some had been shot in the back.