Five Dallas police officers were shot dead and six were wounded after gunmen opened fire during protests against police brutality (video below).
Three suspects are in custody and one suspect is dead after shooting himself during a stand-off with police, BBC reported.
The shootings occurred during the early hours of July 8. Several demonstrators gathered to protest the deaths of Philando Castile in Minnesota and Alton Sterling in Louisiana, who were both killed by police earlier this week.
Dallas Police Chief David Brown said they believe the suspects were all working together, and some used sniper rifles from “elevated positions” to shoot officers in the back when the protest demonstrations were coming to a close.
"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 Brown said.
Brown said one of the suspects told negotiators that “the end is coming” and that he had “bombs all over the place.” That suspect died from a self-inflicted gunshot wound, but police have yet to officially confirm or deny his allegations, according to reports.
No explosives have been found at this time, and police are questioning a woman who was near one of the suspects at the car park where most of the shootings took place. Two other suspects, who threw a camouflaged bag into the area and then sped off in a car were also detained.
"We do not have a comfort level that we have all the suspects,” Chief Brown added.
Brown said 11 officers were shot “ambush style” by sniper fire.
Brent Thompson, 43, one of the officers who died, was a transport police officer with the Dallas Area Rapid Transit (DART).
Another officer who lost his life was identified as Patrick Zamarripa. His stepbrother called him a "hero."
One of the police shootings was captured on video. It shows a gunman taking cover behind a pillar before running toward an officer and shooting him.
One civilian, Shetamia Taylor, was shot in the leg while protecting her kids. She is recovering in the hospital.
Brendan Tyler Hester, a photographer, told BBC:
Once the shots rang out everyone started running. When I turned around to see where my friends were, I saw a policeman next to me get shot. He dropped to the ground screaming. The police shouted at us to run so I did and ended up at the bottom of a parking lot.
There was a shooter on the top of it so I could see all of the shots coming down on to where the police were. I could hear more shouting and screaming. I was trapped with three or four other guys... in the line of fire, so we just had to make a run for it.
Student Tracey Jones said:
We all started to run but I'm disabled and walk with a cane and got knocked over. The police started to shoot back. It looked as if they were shooting into the crowd, even though they weren't, but they were shooting over everyone in the direction of the shooters. It was complete panic.
Along with my friend and about 15 other people, I made it to a train station a few blocks away and we took shelter there for around four hours. I'm in a state of shock, really. I just can't believe this happened in my city.
President Barack Obama described the incident as a "vicious, calculated and despicable attack on law enforcement,” and that "anyone involved in these senseless murders will be held fully accountable.”
“They were on duty doing their jobs, keeping people safe during peaceful protests... they were targeted and nearly a dozen officers were shot,” Obama added. “I believe I speak for every American when I say we are horrified and stand united with the police department in Dallas.”
Obama confirmed that the FBI is working with Dallas police.