Hundreds of protesters in tightly controlled Singapore staged a rare demonstration against the death penalty Sunday as fears grow the city-state is set to carry out a wave of hangings.

Authorities last week conducted the country's first execution since 2019 when they hanged a drug trafficker. Several other death row convicts recently had appeals rejected.

Organisers said about 400 people joined the demonstration at "Speakers' Corner" in a downtown park, the only place in the city-state where protests are allowed without prior police approval.

They held signs reading "Capital punishment does not make us safer", and "Don't kill in our names", and chanted slogans against the death penalty.

"Capital Punishment is a brutal system that makes brutes of us all," Kirsten Han, a prominent local activist, said in an address to the crowd.

"Instead of pushing us to address inequalities and exploitative and oppressive systems that leave people marginalised and unsupported, it makes us the worst version of ourselves."

Protests are unusual in Singapore, which frequently faces criticism for curbing civil liberties.

Hundreds of protesters in Singapore staged a rare demonstration against the death penalty
Hundreds of protesters in Singapore staged a rare demonstration against the death penalty AFP / Roslan RAHMAN

Aside from in "Speakers' Corner", it is illegal for even one person to stage a demonstration without a police permit.

Abdul Kahar Othman, a 68-year-old Singaporean drug trafficker, was hanged Wednesday despite appeals for clemency from the United Nations and rights groups.

Next in line to be executed could be Nagaenthran K. Dharmalingam, a mentally disabled Malaysian convicted of heroin trafficking who lost his final appeal last week.

His case has attracted a storm of criticism, including from the European Union and British billionaire Richard Branson.

Three other men sentenced to death for drugs offences had their appeals rejected earlier in March.

Prosperous but socially conservative Singapore has some of the world's toughest drugs laws, and has faced mounting calls from rights groups to abandon the death penalty.

Authorities insist that capital punishment remains an effective deterrent against drug trafficking and has helped to keep the city-state one of the safest places in Asia.