By Ashley Fantz, CNN. Updated 1:33 PM ET, Sun July 17, 2016
(CNN )LATEST UPDATE
-- One suspect is dead, and two others may be at large
-- Police are looking for anyone wearing army fatigues, all black or possibly a mask
FULL STORY: In a city already tense following a high-profile police shooting of an African-American man, three Baton Rouge police officers were killed and three others wounded Sunday. Officials think the attack on the officers is the work of multiple gunmen.
Police received a call of a "suspicious person walking down with an assault rifle," a source with knowledge of the investigation told CNN. When police arrived, the shooting began. One of the suspects is dead. Authorities believe two others may be at large.
"If they are wearing army fatigues; if they are wearing all black; if they are wearing a mask; if they are wearing anything that's out there, please, give us a call," said Baton Rouge Police Cpl. L.J. McKneely. The shooting took place around 9 a.m. (10 a.m. ET) in the city of about 230,000 people.
"There was no talking, just shooting," McKneely said.
By noon, authorities had secured the scene and were making sure there weren't any explosives left behind.
"After that, we're going to gather as much information as we can and work this case as best as we can to find all individuals that were involved in this," McKneely said. "Somebody might have seen something suspicious; may know of guys plotting to do this. That's why we're reaching out to the community."
Since the shooting death of Alton Sterling by Baton Rouge police earlier this month, the department has worried about credible threats against officers.
It's been an emotionally charged few days across the country because of the protests stemming from the Alton Sterling shooting, and the ambush on Dallas police officers where a sniper killed five officers. "This is an unspeakable and unjustified attack on all of us at a time when we need unity and healing," Louisiana Gov. John Bel Edwards said.
Kip Holden, the mayor-president of East Baton Rouge Parish, said "everything is moving fast."
"There is still an active scene. They are investigating," he said. "Right now we are trying to get our arms around everything."
CNN's Don Lemon, Carma Hassan, Vivian Kuo and Nick Valencia contributed to this report.