Mum on school run takes down carjacker who rammed into her

A US mother driving her kids to school has taken down an armed carjacker who rear-ended her on a busy highway.

Jessica Leismann was stopped at an intersection in Dallas, Texas when the 40-year-old suspect slammed into her minivan amid a high-speed chase with police on Wednesday afternoon.

Ms Leismann and her boyfriend had just picked up their 13-year-old son from school and were on their way to pick up their younger daughter.

She told local news station KXAS-TV that she lost a four-year-old son to epilepsy last year and was spurred to action at the thought of another one of her children dying.

Aerial footage shows the young mum jump from her minivan, drag the suspect from his car and throw him to the ground.

"I jumped out the car and said, 'What the hell is wrong with you, you're in a school zone, what are you thinking?'" Ms Leismann said.

Moments later police swarmed to make the arrest.

Ms Leismann then went to comfort her son, who appeared to be shaken up from the crash.

The suspect is expected to be charged with aggravated robbery and evading arrest.