Four pupils were arrested after a school bus was raided.
The joint operation involved officers from Northumbria Police and public transport operators Nexus and was carried out at 0830 GMT on Wednesday.
The Go Gateshead bus, which was equipped with CCTV, was travelling towards a school in Newcastle.
Four teenagers were arrested - two for alleged possession of cannabis resin and two for the alleged possession of an offensive weapon.
Those arrested are aged between 13 and 16.
A Northumbria Police spokeswoman said officers boarded the bus after information was received.