Drugs worth more than $310,000 were seized from seven suspects in two operations on April 2 and 3.
Officers from the Central Narcotics Bureau (CNB) found more than 1.9kg of heroin, 44g of 'ice', and 44 Erimin-5 tablets, in the operations conducted at Tampines and Yishun.
The seven suspects - six males and one female - were Singaporeans and Malaysians aged between 31 and 49 years old.
They were caught with drugs on them or abusing drugs. CNB officers found more drugs following raids of the suspects' units. The maximum penalty for drug trafficking is the death penalty.