OKLAHOMA CITY - A terrifying home invasion at a metro apartment complex has neighbors on edge. It happened at the Highlands apartments at N.W. 122nd and Penn.

This one has a lot of folks there shaken up. Police say the robbers tied up a man and woman and held them at gunpoint. They even pistol-whipped the man before ransacking their home.

The apartment complex is asking residents to take extra precautions while police look for the people responsible.

When a cry for help came from outside his door, William Kowall didn't hesitate.

"I go ahead and swing open the door. I find the young man who just moved in a week ago. His head's been bleeding, it's been split open, and I hear the girl say, ‘they've got guns,'" Kowall said.

The man and woman had been tied up in their apartment by four armed suspects.

It started when the woman was coming in from the parking lot, and the suspects forced her inside at gunpoint. Police reports show the man was hit in the forehead with a handgun and hit again with a gun in the back of the head.

The robbers tied them up while demanding their "wallets, money, and phones" while threatening to shoot them.

After they took off, the victims ran to Kowall's apartment, and he called police.

"People here just don't feel safe," said Kowall. "I don't even let my girlfriend go outside after dark to even go to the car or go to the store alone."

After the armed robbery Friday morning, managers at the Highlands Apartments left a note on everyone's door to be on alert.

The victims have already moved out.

"Hopefully they get the guys that did this, and it's really unfortunate, especially when it's just a young couple that just moved here," Kowall said.

The robbers got away with three TVs, all the man's credit and debit cards, and more than $500 in cash.

Apartment managers say they're doing what they can, taking on more courtesy officers and adding patrols during the early morning hours.

No one saw the suspects get away in a vehicle, so police say it's possible the robbers live nearby.

Anyone with information on the crime should call Oklahoma City Police.