CYPRESS, Texas -

Two people were killed and at least 22 injured after a gunman opened fire and shot guests at a teenager's birthday party Saturday night in Northwest Harris County.

Investigators said around 11:20 p.m. more than 100 people, mostly teenagers, were at the party at a home on Enchanted Creek Drive at Rising Brook Drive.

The party was apparently publicized on Twitter for days, with more than 100 guests showing up.

"There was a lot of people screaming and crying, yelling, running," said neighbor Dalia Tristan.

Deputies say a person inside had a gun, and opened fire inside, injuring more than 22 people. Witnesses say the shooting happened inside an attached garage of the home and that everyone inside was pushing and shoving while trying to escape.

"Everybody was like scattering everywhere trying to leave, just running everywhere, just doing what they had to do to get out," said Asadd Henry, who attended the party.

Anthony Fisher said his brother and one of his closest friends were shot.

"They called me, he told me they were stuck on 529 -- that's where the party was, like right around the corner from there -- the guys locked the door and pretty much started shooting inside the party," Fisher told Local 2. "My friend said it was pretty much beef between two different sets of guys and they were shooting at each other in the party."

Fisher said his little brother was shot in the hand and is expected to be OK. However, he said his friend was shot multiple times and is still in surgery.

The birthday girl said there were two guests that were unwelcomed.

"My brother and them was patting people down and they didn't want to get patted down so they walked off," she explained.

Only those men, ages 17 and 22 didn't leave, they walked around the house and managed to make their way into the party.

Neighbors and authorities described the scene after the shooting as chaotic.

"I heard between five and ten gun shots ," said neighbor Bruno Figueroa. "But after the gun shots, everybody was scattered. I was watching the commotion and it was just chaos."

"As the deputies were arriving, victims were running down one part of the street and up the other part of the street," said Deputy Thomas Gilliland with the Harris Co. Sheriff's Office. "So many people in one packed area all leaving, (our) potential witnesses and victims were scattered."

The injured were taken to five different hospitals in the area. Some were transported via private vehicles.

One person died at the scene, and another died after being transported to Cypress Fairbanks Medical Center Hospital. At least four other people were taken to hospitals in critical condition.

One neighbor watched as one victim struggled to get away.

"He came out and ran to the car and was banging on the car, 'open the door, lets go, lets go,' and they shot him and he fell right there. We saw him take his last breath," said a neighbor.

We're told three of the victims are in critical condition at Memorial Hermann Hospital.

The victims range in age from 14 to 22 years old.

Harris County Sheriff's Deputies said the motive for the shooting was unclear. Witnesses tell Local 2 that the shooting may have stemmed from an argument.

Deputies are still looking for the two suspects.