Iranian police have stated strenuously that security forces weren't armed with guns during Dec. 27 clashes in Tehran between security forces and protesters.

But newly discovered amateur video, apparently taken with a cellphone, tells a different story.

In the video, a man can be seen and heard opening fire on a crowd of unarmed demonstrators as a man cries out, "Dishonorable Basiji!"

The gunman appears to be a plainclothes security official, perhaps a Basiji militiaman or an intelligence operative working for the Revolutionary Guard.

Witnesses say such forces have been trying to terrorize protesters.

But there's a twist.

Even though he opens fire on the crowd, possibly wounding or killing demonstrators, the protesters don't scatter away.

Instead they fight back.

"Attack!" someone calls out.

The 47-second clip then shows the crowd of unarmed demonstrators, mostly men of all ages, chasing after the gunman.

-- Los Angeles Times

Video: A gunman's bullets don't scare off a crowd of unarmed demonstrators. Credit: YouTube