US on edge after police killings

“We are hurting,” Dallas Police Chief David Brown said during a press conference early Friday. “We are heartbroken.

“All I know is that this must stop, this divisiveness between our police and our citizens.”

President Barack Obama, who is in Poland to attend a NATO summit, said the U.S. was "horrified" by the "vicious, callous and despicable attack on law enforcement.

"I believe I speak for every single American when I say that we are horrified over these events and that we stand united with the people and the police department in Dallas," he said before later ordering flags on federal grounds to be flown at half-mast until July 12.

Presidential candidates also condemned the attack.

Hillary Clinton mourned for the officers "shot while doing their sacred duty”, while Donald Trump called for "leadership, love and compassion" in the wake of shootings.

Dallas Mayor Mike Rawlings said, "Our worst nightmare happened. It is a heartbreaking moment for the city of Dallas.”

Texas Gov. Gregg Abbott ordered state flags be lowered to half-staff to honor the victims.

The top prosecutor in the U.S. said at a press conference that the events this week left Americans with a feeling “of helplessness, of uncertainty and of fear.”

While these feelings were “understandable”, Attorney General Loretta Lynch said, “the answer must not be violence. The answer is never violence,” she said. “We must continue working to build trust between communities and law enforcement.”

She also encouraged the continuation of peaceful protests. “We must reject the easy impulses of bitterness and rancor and embrace the difficult work of finding a path forward together,” she added.

Parts of downtown Dallas remained on lockdown Friday.

Violence erupted late Thursday at a Black Lives Matter rally in the downtown area, where 11 police officers were shot, most of them by sniper fire from “elevated positions”, according to officials.

Police arrested three suspects and engaged a fourth throughout the better part of the night, as reports of officers' deaths arrived one after another.

An active shooter situation went on for hours in a parking garage near El Centro College on Main St., where the fourth suspect was holed up, shooting at officers as they tried to negotiate.

The suspect told them that the "end is coming", that he would "hurt and kill more" officers, and bombs were planted "all over the place" downtown, Brown said.

"Negotiations broke down, we had an exchange of gunfire with the suspect," he said.

The police chief said law enforcement "saw no other option but to use our bomb robot", a device sent in to the suspect and was detonated, killing him.

"Other options would have exposed our officers to great danger," the chief said.

Brown then went on share comments from the suspect, elicited before he died by a police negotiator who "did an exceptional job".

The suspect told officers he was "upset about Black Lives Matter" and recent police shootings, Brown said.

"The suspect said he was upset at white people. The suspect stated he wanted to kill white people, especially white officers," Brown said.

The suspect, who remained anonymous throughout the briefing, said he was not affiliated with any group.

Media reports named the suspect as 25-year-old Micah Xavier Johnson, who had no criminal record or known links to terrorism.

A U.S. Army spokesman confirmed to independent army newspaper, Stars and Stripes, that the suspect was an army veteran. There has been no official corroboration.

A statement from the family of Alton Sterling, the 37-year-old black male who was killed earlier this week in an encounter with two police officers in Baton Rouge, Louisiana, condemned the violence. "Regardless of how angry or upset people may be, resorting to this kind of sickening violence should never happen and simply cannot be tolerated,” the family said in a statement. "Responding to violence with violence is not the answer."

Thursday's attack, described as one of the deadliest on law enforcement since 9/11, came on the heels of two fatal police shootings caught on video that took the lives of two black men on consecutive days.

Sterling, who sold CDs outside a convenience store in Baton Rouge, was shot dead while pinned down to the ground by two white police officers.

Video footage from two different angles revealed the details of the shooting, prompting nationwide protests against police brutality.

Another video, this time a Facebook live stream, shed light on the aftermath of another fatal shooting, which killed 31-year-old Philando Castile at a traffic stop in St. Paul, Minnesota, unleashing growing resentment and frustration that boiled over in otherwise peaceful protests in several cities Thursday, including New York City, Atlanta, Chicago, and Dallas, where they turned deadly.

A multi-faith prayer service is planned in the city for noon.

Anadolu Agency