Here's what we know this morning about the attack on Dallas police officers

An attack on police officers by at least four men during a Black Lives Matter protest in Dallas last night has sadly left five officers dead:

It has been a devastating night. We are sad to report a fifth officer has died.

— Dallas Police Dept (@DallasPD) July 8, 2016

#BREAKING ~ 5 officers dead after shooting at downtown Dallas protest. 4 DPD, 1 DART PD https://t.co/pBdHa8nFqM pic.twitter.com/ikfCRBOhVj

— FOX 4 NEWS (@FOX4) July 8, 2016

Two of the wounded are civilians:

LATEST: 12 officers shot, 5 killed, 7 injured; 2 civilians shot and wounded – Dallas Mayor's office

— BNO News (@BNONews) July 8, 2016

Three suspects are in custody, and a fourth reportedly died of a self-inflicted gunshot wound.

#Dallas, what we know so far:
-5 police officers killed, total of 12 shot
-3 alleged suspects in custody
-4th suspect dead after standoff

— CNN (@CNN) July 8, 2016

The suspects in custody are uncooperative:

"Are the suspects in custody cooperating?" @SavannahGuthrie
"They’re not…they're being pretty tight-lipped." #Dallas Mayor @Mike_Rawlings

— TODAY (@TODAYshow) July 8, 2016

Dallas Police Chief David Brown held a press this morning and provided more details, including information about one of the suspects:

Chief David Brown: "We are heartbroken. There are no words to describe the atrocity that occurred to our city." https://t.co/QtqZywIweZ

— MSNBC (@MSNBC) July 8, 2016

#Dallas Chief: Suspect said he was "upset at white people, wanted to kill white people, especially white officers."https://t.co/ygYQAJlFfL

— CBS This Morning (@CBSThisMorning) July 8, 2016

#BREAKING: @DPDChief: "We're hurting. Our profession is hurting. Dallas officers are hurting. We are heartbroken."

— Jason Whitely (@JasonWhitely) July 8, 2016

#BREAKING: @DPDChief: "We cornered one suspect and we tried to negotiate for several hours" at El Centro College.

— Jason Whitely (@JasonWhitely) July 8, 2016

#BREAKING: @DPDChief: "The suspect is deceased as a result (of a robot) detonating a bomb. Reports of him killing himself is not accurate."

— Jason Whitely (@JasonWhitely) July 8, 2016

#BREAKING: @DPDChief: Suspect said he was upset about Black Lives Matter. Said he was upset at white people. Wanted to kill white ofcrs.

— Jason Whitely (@JasonWhitely) July 8, 2016

#BREAKING: @DPDChief: Suspect said he was not affiliated with any group but operating independently.

— Jason Whitely (@JasonWhitely) July 8, 2016

#BREAKING: @DPDChief praised bravery of @DallasPD and DART officers for running toward gunfire from an elevated position.

— Jason Whitely (@JasonWhitely) July 8, 2016

#BREAKING: @DPDChief: "Please join me in applauding these brave men and women who do this job under great scrutiny."

— Jason Whitely (@JasonWhitely) July 8, 2016

#BREAKING: @DPDChief: Grieving officers families need your prayers.

— Jason Whitely (@JasonWhitely) July 8, 2016

Police think it’s possible more suspects could be at large:

#BREAKING: @DPDChief: "If there's someone out there who's associated with this we will find you." Didn't say whether others were out there.

— Jason Whitely (@JasonWhitely) July 8, 2016

NEW: @DallasPD not completely comfortable they have all suspects located. #DallasShooting

— FOX 4 NEWS (@FOX4) July 8, 2016