Dallas, USA (BBN)– Four Dallas police officers have been shot dead by sniper fire during protests against the shooting of black men by police, authorities say.
Police are in a standoff with one armed man in a garage. Three other people have been detained, reports BBC.
Gunfire broke out at around 20:45 local time on Thursday (01:45 GMT Friday) as demonstrators marched through the city.
The protests were sparked by the deaths of Philando Castile in Minnesota and Alton Sterling in Louisiana.
Dallas Police Chief David Brown said officers remained in a stand-off with one armed man at a garage who was firing off rounds with a rifle and had claimed to have planted bombs.
Chief Brown said that a woman who was in the vicinity of the armed man was now being questioned.
Police also said officers had intercepted a car after a person threw a camouflaged bag into the back and sped off. Two occupants were being questioned.
Chief Brown said the suspects were all believed to have been working together, using rifles to carry out attacks while the rally was taking place.
He added: “We do not have a comfort level that we have all the suspects.”
He had earlier said 11 officers were shot “ambush style” by the sniper fire, killing three. Police later tweeted that a fourth officer had died. One of those killed was a transport police officer.
The police said it appeared that two snipers had fired from “elevated positions” during the protest rally.
“We believe that these suspects were positioning themselves in a way to triangulate on these officers from two different perches… and planned to injure and kill as many law enforcement officers as they could,” Chief David Brown said.
The mayor of Dallas, Mike Rawlings, said it was a “heartbreaking moment for the city”.
One of the march’s organisers, Rev Jeff Hood, saw people scramble for cover as gunfire rang out.
“I ran away from the shots trying to get people off the streets and I was grabbing myself to see if I was shot,” he told the Dallas Morning News.
Police issued a photo of one man with a rifle slung over his shoulder. Police later tweeted that he had handed himself in. It is unclear if he was involved in the shooting
Flights over Dallas have been restricted.
Captured on video
The Dallas protests were among several held across the US over the police use of lethal force against African Americans.
Philando Castile was shot dead at a traffic stop in St Paul, Minnesota , on Wednesday, while Alton Sterling was killed by police a day earlier in Baton Rouge, Louisiana.
Both incidents were captured on video, reigniting what has become a national debate.
US President Barack Obama said “all fair-minded people should be concerned” about the frequent police killings of black Americans.
Pointing to statistics showing African-American citizens are far more likely to be shot by police by whites, Mr Obama called on law enforcement to root out internal bias.
“When incidents like this occur, there’s a big chunk of our fellow citizenry that feels as if it’s because of the colour of their skin, they are not being treated the same,” he said. “And that hurts.”
But Mr Obama also said there was “extraordinary appreciation and respect for the vast majority of police officers who put their lives on the line to protect us every single day. They’ve got a dangerous job. It’s a tough job.”