Three men are in jail after police said they kidnapped a 15-year old girl and assaulted her in a van early Tuesday.

The girl escaped the van when Southern Methodist University police pulled the van over for driving erratically.

Police said the girl accepted a ride in the van as she was walking on McMillan Avenue in Dallas at about 4:30 a.m. She was heading to a relative's home on Eastside Avenue, about two miles away.

"Our victim was trusting," Dallas Police Maj. Rob Sherwin said. "Not everybody is like this, but obviously there’s a safety note for everybody."

Sherwin said the girl discovered there were three men in the van as soon as she got in. She protested, which is when Sherwin said they began assaulting her while driving around East Dallas for an hour and a half.

At about 6 a.m., Sherwin said the men drove onto the SMU campus where the suspicious van was reported for driving erratically and stopped by SMU police.

The victim escaped and SMU police arrested Mexican citizens 35-year-old Vraulio Valencia Hernandez, 36-year-old Antonio Hernandez Cabrera and 57-year-old Rogelio Bedolla Munoz. Each man is charged with aggravated kidnapping and U.S. immigration officials have been notified of the arrests.

Sherwin said the suspects have no prior Texas arrest record.

"I'm very thankful, No. 1, for the SMU police stopping that van and for the citizens, or the people at SMU who notified this police department to stop this assault," Sherwin said.

Investigators said they do not think this attack is related to the sexual assault at knifepoint of an SMU student who was jogging near campus Sunday night.