Updated at 12:33 a.m. ET on July 8
Two gunmen shot eleven police officers in Dallas, Texas, during a protest on Thursday night, killing at least four of them. The death toll makes this one of the deadliest days for police in the history of American law enforcement.
At a Thursday night press conference, Dallas Police Department Chief David Brown said the suspects threatened to place a bomb in the downtown area and that his department was coordinating with federal agencies.
One suspect is in custody after a shootout with SWAT officers, the Dallas Police Department said in a statement. Brown earlier said a suspect had been “cornered,” but did not offer further details. It’s unclear whether there are still suspects at large.
“Tonight it appears that two snipers shot ten police officers from elevated positions during the protest/rally,” Brown said in an initial statement. “Three officers are deceased, two are in surgery, and three are in critical condition. An intensive search for suspect is currently underway.” The police department later said an eleventh officer had also been injured and a fourth officer had been killed.
On Thursday, five police officers were killed and seven were injured after a sniper attacked a public protest march in downtown Dallas, Texas. Sources indicate at least three other people were taken into custody for questioning relating to the attack. The march was held to protest the shooting deaths of Alton Sterling in Louisiana and Philando Castile in Minnesota during engagements with police officers.

Police identified 25-year-old Micah Johnson as the suspect. Johnson had previously served in the US army, and police reported he said he wanted to exact revenge upon police officers after news of Sterling and Castile's deaths. Ammunition and weapons were found inside Johnson's home. Dallas Police reported the policemen were shot at from a height. Officials said two civilians were also injured in the attack. 
File photo of police car lights.
Micah Johnson served for the  from 2009 until early 2015, including a tour of Afghanistan. Johnson had no criminal record.  His attack was reported to be a lone mission.

After the attack earlier on Thursday, police killed Micah Johnson in 's parking lot by a bomb explosion.

Hillary Clinton, 2016 United States presidential election candidate and favorite for the Democratic nomination this July, said, "There is too much violence, too much hate, too much senseless killing, too many people dead who shouldn't be. No-one has all the answers. We have to find them together." 

After Johnson was killed, , Dallas' mayor, said "We believe now the city is safe".