Central Narcotics Bureau (CNB) officers arrested 24 suspected drug offenders and seized 1.9kg of "mushroom" substances with drug-like properties during raids.
Officers nabbed 19 suspects in Lorong 10 Geylang around 8pm on Tuesday, including two men aged 38 and 49 suspected of drug trafficking.
About 1.8kg of vegetable matter containing new psychoactive substances, colloquially known as "mushroom", was also seized during the blitz.
CNB also raided a unit in Cassia Crescent, off Guillemard Road, and arrested a 54-year-old man suspected of drug trafficking and a woman, 33, suspected of drug abuse.
A total of 78g of vegetable matter containing "mushroom", 104g of powder with "mushroom", and three bottles of acetone - two of which were mixed with the "mushroom" powder - were also found.
Three other suspects associated with the 54-year-old man were arrested in various locations, including a 46-year-old man in Ang Mo Kio Avenue 1 and two men, aged 42 and 46, at Odeon Katong.
Under the Misuse of Drugs Act, the consumption, possession, trafficking, import or export of any controlled drugs is an offence.
Those found guilty of trafficking these controlled drugs may be jailed for at least five years and get five strokes of the cane.
Repeat offenders or those who sell drugs to underage abusers face further penalties.
CNB said it takes a zero-tolerance stance towards drugs, including "mushroom", which mimics the effects of other drugs such as cannabis, cocaine and Ecstasy.
Abusing "mushroom" is linked to physical and psychological reactions including paranoia, seizures, hallucinations and death, said the bureau.