FOUR teenagers have been accused of carving a swastika into a classmate’s forehead in a shocking kidnapping and torture case in Portland, Oregon.

Investigators say the group attacked the 16-year-old in revenge for calling their friend “gay” on Facebook.

The attack was so vicious that three of the accused will be tried as adults.

Police will allege that Jenna Jean Montgomery, 15, lured the victim to a shed behind a house in Southeast Portland on February 10 with the promise of drugs and sex, the Oregonian reported.

She later told police she’d acted as “bait”.

When the victim arrived at the shed, he was confronted by three boys named as Jess Taylor, 17, Blue Kalmbach, 15, and a 14-year-old boy.

The victim told police that he was struck in the back of the head with a crowbar as he entered the shed.

Kalmbach then allegedly shot the victim in the hand, chest and groin with a BB gun, and proceeded to carve a “swastika-shaped insignia’’ into the victim’s forehead with a box cutter, according to the Oregonian.

The teens took the victim’s iPod and ordered him to fetch a sum of money and a skateboard. Instead, the victim escaped and ran to a nearby auto shop to call for help. The four alleged attackers were arrested later that day.

Police said the suspects considered their victim a bully, and saw their acts as retaliation. But the victim’s mother Kelli Murrain told KPTV there was no excuse.

“He’s been really emotionally and mentally traumatised. It’s something he’s going to live with, especially if the scar of the swastika doesn’t go away. Every time he looks in the mirror, he’s going to have that memory,” she said.

“I’m almost ready to lose faith in humanity ... all this evil is running around and it’s with our youth.”

Police have charged the teens with kidnapping, assault, and robbery. All four have pleaded not guilty. A grand jury was expected to return an indictment next Tuesday.