(UPDATE 3:40 a.m.)-NBC DFW is reporting 3 suspects are in custody at this time, 2 men and 1 woman. The 4th suspect was the one who shot himself in the El Centro parking garage. Police are starting to leave the scene. Closures are expected in the downtown area today.

(UPDATE 3:02 a.m.)- Suspect is confirmed dead from self-inflicting gunshot wound.

(UPDATE 2:51 a.m.)- Sources on scene are confirming that the suspect has shot himself. KTAB/KRBC are working to confirm if suspect is dead. The American Red Cross has arrived to the scene to assist police officers.

(UPDATE 2:24 a.m.) NBC DFW is reporting the threat has been neutralized.

(UPDATE 1:56 a.m.) – According to the Dallas Police Association, a 5th police officer has died after being shot in downtown Dallas.

(CNN)[Breaking news update 12:41 a.m.]

Dallas police are negotiating with a suspect at a parking garage in downtown Dallas, Chief David Brown said. Police have been exchanging gunfire with the suspect for 45 minutes.

“The suspect has told our negotiators that the end is coming,” Brown said.

He told officers that he is going to hurt and kill a lot of them, and said he’s placed bombs in downtown Dallas.

[Previous story posted at 12:06 a.m.]

Four police officers were killed in downtown Dallas as crowds protested the fatal shootings of two African-American men by police in Louisiana and Minnesota.

Dallas police said a total of 11 officers were shot during the protests, including the four shot dead.

Here’s what we know:

— A total of 10 police officers were shot during the protests, Dallas Police Chief David Brown said. An 11th was shot during an exchange of gunfire with one of the suspects, and the officer was transported to the hospital, authorities said.

— Brown said there could be more than two shooters. He said police had cornered a suspect in a commercial garage. “These suspects have threatened to plant a bomb in the downtown area,” he said.

— Two of the shooters were snipers, who shot from an “elevated position” and fired on officers “ambush-style,” he said.

— Officers killed included one DART officer and two Dallas police officers. DART, the Dallas Area Rapid Transit agency, operates buses and commuter rail in the city and surrounding suburbs.

— The Dallas Police Department circulated a photo of a man they said was a suspect in the shooting, but later called him a person of interest and said he turned himself in.

— An “alleged suspect” is in custody, the Dallas Police Department tweeted.

— A suspicious package was discovered near that suspect’s location. The package is being secured by a bomb squad, the tweet said.