The man, who called from a phone booth at Block 10 Haig Road on Thursday at about 5.10 pm, also threatened to attack multiple locations, said a police statement on Friday.

Police investigations are on-going.

Police also warned the public that that they will not 'hesitate to take firm action against persons committing such offences.'

A massive land, sea and air search is continuing to hunt down Mas Selamat, 47, leader of the Singapore JI terror network, who fled from Whitley Road Detention Centre on Wednesday afternoon.

Posters of the wanted fugitive - one showing him with a moustache and goatee and the other, clean-shaven - have been put up at many public places and immigration checkpoints to urge people to call 999 immediately if they spot him.