A man has been taken from police custody after three men armed with knives attacked a security van outside a magistrates court.
Forensic teams examined the security van outside the court
Police said Aaron Williams was heard shouting "Don't let them take me" as three men dragged him from the GSL security van outside the Salford court.
The driver was punched in the face during the incident.
Police said they have not ruled out the possibility that Mr Williams was taken against his will.
The 21-year-old from Lower Broughton, was due before magistrates after being arrested for not appearing in court.
He was detained for failing to appear on a theft charge and was being transferred from Swinton police station to court following his arrest on Wednesday.
Greater Manchester Police said they were alerted to reports that three men armed with kitchen knives had attacked the security van just after 0750 GMT.
They said he was "dragged and bundled" into a stolen car, which was later found abandoned.
Services company GSL, which was responsible for the transfer, described the escape as a "very serious incident".
It said the van was waiting to go through a barrier to enter the court's secure car park when it was targeted.
The men slashed the van's front tyre, before punching the driver and threatening a female security officer.
"Our prisoner custody officers have been threatened with violence and one has received injuries which we think are as a result of being punched," a spokesman said.
"This is a very unusual incident. When this level of extreme violence is offered or used there is very little that we can do."
Aaron Williams was arrested for failing to appear at court
Forensic teams examined the white Mercedes van, before towing it away for further tests.
Det Insp Danny Woodward, of Greater Manchester Police, said: "There are concerns at the moment about the exact circumstances of this incident and I'd like to reassure the public that we are doing all we can to trace Aaron."
Police said it is not yet clear whether Mr Williams was involved in the escape, or if the gang abducted him.
Two police cars remained parked in front of the building on Thursday while normal court business carried on inside.
Student Iain Wilson, 25, of nearby Kays Gardens, who can see the security gates from the rear of his property, said he thought the escape was "inevitable".
"I think they can only process one van at a time inside so the others have to wait outside with the prisoners inside the vans," he said.
"You have a situation where each security guard has to get out of their vehicle and press a buzzer on the wall outside to get in rather than automatically go through."
The three men were white, about 5ft 6ins or 5ft 7ins tall and athletic build. They are believed to be in their early 20s and spoke with local accents.
GSL Services is responsible for conducting about 700 prisoner transfers across the UK every year.