Two more teenage boys have been charged with grievous bodily harm and other offences over the alleged robbery of a 75-year-old man in Toowoomba.
Police allege the man was waiting at a Margaret Street taxi rank around 5pm on Monday when he was pushed from behind.
The man, who police said was "minding his own business", fell to the ground and sustained serious injuries.
Police allege his backpack was then stolen.
The man was taken to hospital in a critical condition, where he remains with serious head injuries.
Queensland Ambulance Service Officer Bradley Setch said the victim went into cardiac arrest and had to be revived by paramedics.
Toowoomba Detective Inspector Heath McQueen said on Tuesday the man's injuries were "not survivable".
An 18-year-old man and 16-year-old boy were taken into custody later on Monday night and charged, and they have since faced court.
On Wednesday, police took another 16-year-old and a 17-year-old into custody at a Drayton address and later charged them with multiple offences.
The 17-year-old boy was charged with armed robbery with violence, grievous bodily harm and unlawful use of a motor vehicle, while the 16-year-old was charged with armed robbery and grievous bodily harm.
A 15-year-old boy and a 13-year-old boy were also taken into custody at the same property as the two older boys, and charged with multiple offences unrelated to the taxi rank incident.
Police said in a statement that they are providing ongoing support to the family of the 75-year-old man.
