Singapore hanged three people for drug offences last week, bringing the total number of executions to 17 this year - the highest since 2003, BBC reported.
These come a week before a constitutional challenge against the death penalty for drug offences is due to be heard.
Singapore has some of the world's harshest anti-drug laws, which it says are a necessary deterrent to drug crime, a major issue elsewhere in South East Asia, according to BBC.
