Two female cadets have said they were violently threatened after leaving a Army Reserve centre in Tyneside.
The threats are understood to have been "graphic and nasty" and included a comment about beheading.
The teenage girls said the comments were made by two men driving a car close to the Gateshead Army Reserve Centre, in the evening of 21 January.
Northumbria Police said inquiries were continuing to establish exactly what was said to the cadets and that extra patrols were being carried out in the area.
Gateshead Superintendent Richie Jackson said in a statement: "The men made no attempt to make any physical contact with the girls or get out of the car, and shouted the comments while driving away from the scene.
"Inquiries are on-going to establish the exact nature of what was said during the incident and we have spoken to the two teenage girls, viewed CCTV footage from the area and have identified the vehicle and inquiries are on-going to trace the driver."
Officials from the local army cadets were unable to comment on the incident.
The two men are thought to have been driving a silver Vauxhall Zafira. The driver was described as black or Asian, in his 40s, of plump or muscular build, with a black bushy beard and dark clothes.
The passenger was described as black or Asian, in his 30s, with short black hair and stubble.
A Ministry of Defence (MoD) spokesman said the safeguarding and protection of young people was taken "very seriously".
An MoD statement said: "We are aware of an incident allegedly involving members of the Army Cadet Force - this is a matter for the police and we cannot comment further. Any witnesses are urged to contact the police.
"We understand the girls were not in uniform at the time of the incident and that the suspects asked them 'Are you in the Army?' before issuing the threats."
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