Police say that £240,000 worth of suspected cannabis was found in a car on the Victoria Road in Derry.
The car was also involved in a collision on the Victoria Road with a police vehicle around 6.30 pm.
Two men aged 28 and 30 were arrested on the Victoria Road in Derry for having a suspected class B controlled drug with intent to supply.
They are currently being detained at Strand Road PSNI station.
The Victoria Road has now re-opened after it was closed for a period after the crash.
None of the occupants of the drug car or the police vehicle needed hospital treatment.
Later, £60,000 worth of suspected cannabis was found in a car at the Hillsborough roundabout area.
A 36-year-old man was arrested in the Hillsborough area for having a suspected class B controlled drug and possession of a suspected class B controlled drug with intent to supply.
Detective Inspector Alan Pyper was delighted that £300,000 worth of suspected drugs had been prevented from reaching street dealers.