The teens connected online before the victim met up with them and underwent a terrifying ordeal.

A teenager has been charged after a 15-year-old boy was allegedly stuffed into a car boot and assaulted with a hammer and knife.

The alleged attack happened around several locations near Ipswich, about 40 minutes south-west of Brisbane, Queensland, on Sunday.

Queensland Police Service (QPS) alleged two boys, aged 14 and 15, connected with a 17-year-old boy on social media earlier that day.

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About 6pm, the 17-year-old boy attended a Moorooka residence with a second boy in a car, where they met with the 14 and 15-year-old boys, before all four drove to Redbank Plains.

Once there, it's alleged the 17-year-old boy threatened the two younger boys with a knife.

Both tried to run, but the 15-year-old was caught and forced into the boot of the car.

The vehicle was driven to New Chum where police said the boy was pulled from the boot and allegedly repeatedly assaulted with the knife and hammer for around 20 minutes.

He eventually managed to escape and flagged down help from a member of the public.

The 15-year-old was taken to hospital in a stable condition. The 14-year-old boy was not physically injured.

A crime scene was declared overnight at a property on Old Toowoomba Rd in One Mile.

Officers arrested a 17-year-old boy from the area.

He has been charged with deprivation of liberty, torture, wounding, armed robbery, assault occasioning bodily harm and possession of a drug utensil.

He is due to appear in Ipswich Childrens Court on Monday.

Police said the investigations are ongoing and are urging anyone with information to come forward.