Singapore on Thursday made a rare public apology after its top terrorist suspect escaped from a heavily guarded detention centre in an embarrassing security lapse.

Mas Selamat bin Kastari, the alleged head of the Singapore branch of Jemaah Islamiyah, south-east Asia’s main Islamist terrorist group, was still at large on Thursday, more than 24 hours after his escape, in spite of a massive manhunt. “This should have never happened. I am sorry that it has,” said Wong Kan Seng, the home affairs minister who oversees the internal security department that has held Mr Mas Selamat since 2006.