against the recent police shootings of two African Americans in the last three days

The police are closing in on the snipers, but many of the details are still unknown

Oh Soo-Young reports. Five policemen have been shot dead, and

six other officers wounded during a mass rally in Dallas, Texas over the fatal police shootings of two African American men this week

Around 9 p.m. local time, a group of snipers opened fire from elevated positions, hitting 11 officers

"I was walking and the snipers just started shooting, man. Like, all of the cops were

getting shot, man. I just saw cops bending over, man. There had to be like five or six

cops. They were all getting shot down, man"

According to Dallas Police Chief David Brown, it's unclear how many gunmen there were but

three suspects are currently in custody, and the fourth was cornered by officers at a

downtown garage. One suspect was arrested after a shootout

with authorities, and a suspicious package discovered nearby was secured and inspected

by a bomb squad, according to the police. Another suspect turned himself in after his

picture was posted on Twitter by the police, calling the man a "person of interest"

He was later released after questioning. The police also said, an individual spotted

with a camouflage bag had thrown it into a vehicle before driving off at high speed

Both occupants of the car were detained

The incident comes amid mounting public outrage over Wednesday's shooting of Philando Castile

the second black American to be shot and killed by police this week.

Castile's fiancee, who was with him in the car at the time, said he'd been shot four

or five times "for no reason," as he moved to take out his license and registration

She streamed his final moments on Facebook as he slumped, bleeding, against the driver's

seat. As the video circulated, thousands took to

the streets in protest across the country, in Washington, D.C., New York, Philadelphia

and Minnesota. According to data from the Washington Post

more than 500 people have been shot to death by police this year

Castile is believed to be the 123rd African American among them to have met this fate

Oh Soo-Young, Arirang News.