KARACHI: Authorities are investigating a video that appears to show paramilitary forces shooting to death an unarmed young man in Karachi, officials said Thursday.

The video aired repeatedly on TV.

A spokesman for the paramilitary Rangers claimed its forces detained 25-year-old Sarfaraz Shah because he was attempting to rob people in a park in Karachi on Wednesday. He said a gun was recovered from Shah and he was shot because he was reaching for a Ranger's rifle.

Shah's brother, Salik, a local crime reporter, denied his brother was a robber and accused the Rangers of shooting an innocent person.

''It seems to be a case of routine high-handedness of the Rangers,'' Salik Shah said. ''They misuse their powers by shooting on sight.''

The video aired on local television shows a man in civilian clothes holding Sarfaraz Shah by his hair and kicking him toward a group of five Rangers. One Ranger points his rifle at Shah's neck as he appears to plead with them. As Shah moves toward a Ranger with his arms outstretched, he is shot and falls to the ground.

The Rangers' spokesman said he was shot in the leg and eventually died.

Both the Rangers and the police said Thursday that they will investigate the incident.

Last month, security forces shot and killed five foreigners at a checkpoint near Quetta. Officials initially claimed the five were suicide bombers, but they turned out to be unarmed and video of the shooting further undercut their claim. The government has since launched an inquiry into the shootings.