Washington, April 22 (IANS): The US Justice Department on Tuesday launched a civil rights investigation into the death of an African-American man earlier this week.

Freddie Gray, 25, died on Sunday, a week after he was arrested on April 12 on a weapons charge in the city of Baltimore in the US state of Maryland, according to a Xinhua report.

Gray reportedly suffered spine injuries and lapsed into a coma after his arrest by the police.

According to a mobile phone video, which recorded the arrest, Gray was pinned to the ground and then bundled into a police van. He was heard screaming on the video.

The Baltimore Police Department on Tuesday released the names of six police officers involved in the case and they have been suspended, according to a CNN report.

Protests broke out in Baltimore late on Tuesday with demonstrators chanting "No justice! No peace!"

They marched to a local police station that was protected by barricades. One person was arrested after crossing the barricade, but the protest was largely peaceful.

Among the crowd were members of Gray's family, including his mother. She held her head and cried. Many of the protesters clasped hands and raised them in a show of support.

"Make some noise for Freddie Gray," one man shouted into a megaphone.

Police, however, said that none of the six officers involved in the case described any use of force, according to a report.

The video triggered several days of protests in Baltimore and the city's Mayor, Stephanie Rawlings-Blake, said she was "angry" and "frustrated" and promised a thorough investigation.

The police probe will be completed by May 1 and findings will be turned over to the city's chief prosecutor, who will determine whether to bring criminal charges in state court.