THE school friend who witnessed a teenage girl being dragged from a toilet block by her ex-boyfriend said the male was whispering threats in her ear as he pulled her by the arm.

Police today say they still hold grave concerns for the welfare of Mona-Lisa Tafengatoto, 14, who was taken from Eagle Vale High School yesterday by her ex-boyfriend Tovila Tufuga, despite claims she has run away in six previous occasions.

A school girl who was in the toilet block getting changed when the alleged abduction occurred told The Telegraph she was "worried sick" for Mona-Lisa.

"I'm the last one who saw her being dragged away," the girl said.

"She was crying and he was threatening her...whispering nasty things in her ear," she said.

The witness, who has been interviewed by police, said Mona-Lisa was getting changed in the toilets, into shorts because of the hot weather, when her former boyfriend came in yelling.

"She looked scared to see him," the girl said.

"He made her go with him...pulled her by the arm."

The witness said she ran to alert a teacher, who then called Triple-0.

It is understood Mona-Lisa lives at Claymore with her ex-boyfriend's family, although Tovila no longer lives there.

Tovila's father Mike, who is Mona-Lisa's guardian, said she has run away on six previous occasions, and he hoped this was no different and she'd be found safe and well.

Police said they have had multiple unconfirmed sightings of the pair since they were seen leaving the school at lunchtime yesterday.

A search is still underway for the pair.

A female teacher contacted police after seeing Mona-Lisa forcibly removed.

The young woman was crying and visibly distressed, with the teacher fearing for her safety if she tried to physically intervene.

Police allege the assailant is a former boyfriend of the girl, 16-year-old Tovila Tufugaa, who is also a former student of the school.

It is believed they were in a relationship, but broke up last year.

Officers have asked for the public for urgent assistance to locate the teens.

The teacher who witnessed the abduction said the pair were last seen heading east on Drysdale Street towards Claymore, where both of the young people live.

Inspector Brad Ainsworth from Macquarie Fields Local Area Command said an extensive search of the local area has failed to locate the missing girl.

"We've got concerns because of the circumstances of her being removed from the school,'' he said.

"She was dragged against her will and she was crying.''

Tufugaa is described as being of Pacific Islander appearance, 175 cm tall, medium build, brown eyes, black hair, and wearing a faded black hooded jumper, black shorts, and a black hat. He has a tattoo on his left neck of his last name.

Ms Tafengatoto is described as being of Pacific Islander appearance, 170 cm tall, solid build, brown eyes, long brown hair which is back, and wearing a white shirt, black tracksuit pants and black shoes with white soles. She was also wearing a black backpack.

There are reports the pair were spotted at Hungry Jacks in Cabramatta about 2pm yesterday.

Police are asking the public to be on alert and report any sightings of the pair.