About 40 officers carried out patrols and stop-and-searches in Edinburgh's Leith area on Tuesday as part of Operation Wolf.
Four people were arrested for drug and warrant offences after police were led to several properties in Midlothian where they recovered heroin, £3000 in cash and suspected stolen goods. Officers visited 28 licensed premises and issued five people with fixed-penalty notice tickets related to anti-social drinking.
A further 16 people were reported to the procurator fiscal for road traffic offences.
Police Scotland said the operation had yielded "vital intelligence" on ongoing criminal activity that will be followed up, and further enforcement days are planned.