A 30-year-old man has been arrested and charged over a fire in front of a neighbourhood police post (NPP) in Boon Keng, the police said.

No one was injured in the incident, which the police said was not an act of terrorism.

The man, who acted alone, had set fire to a few bags of clothes using petrol or diesel and smashed the glass door of the NPP, the police said.

Although he had scribbled "ISIS" on several pillars near the police post, preliminary investigations showed that he was a "disgruntled person unhappy with the perceived social inequality", the police said.

Singaporean Sivaprakash Mailravanan was charged yesterday with mischief by fire.

He will be remanded for further investigations and the police will seek a court order to send him for psychiatric assessment.

When The Sunday Times got to the scene yesterday morning, shortly after midnight, vulgarities were scrawled on the void deck walls surrounding the police post.

"ISIS" was visible on at least three walls. The glass panels of the police post at Block 105 Towner Road were also shattered.

Residents reported hearing loud explosions from the police post around 11pm.

Ms Renie Cheong, 17, said she saw the fire erupt in front of the police post as she was walking home from nearby Boon Keng MRT station.

As the fire was raging, said Ms Cheong, a man walked to a lorry parked in front of the station to retrieve a spray paint can and scrawled "ISIS" on a nearby wall

"I was quite calm, but I was thinking who would want to play with fireworks down here," she said.

Ms Cheong said that the man had also jumped on top of the vehicle and scattered poker cards on the floor after spraying graffiti on several walls.

There was music blaring from the lorry, she added. There were at least five to six successive "explosion-like" sounds, she said.

Mr Frankie Wong, 60, said that he had heard the explosions from two blocks away and rushed down after seeing smoke emanating from the police post.

"I knew it was something big, so I ran down," said the Towner Road resident.

Videos of the incident circulating on social media show a man stripping off his top with what looks to be a knife in his hand, as firemen put out the fire behind him.

Senior Minister of State for Defence Heng Chee How, an MP for Jalan Besar GRC, said on Facebook that the police post was unmanned. It is a fully automated police post.

He said that he was relieved no one was hurt, and had reassured residents at the scene that the police will ensure the estate is safe and secure.

The Singapore Civil Defence Force said that the fire, which also involved aerosol cans, was extinguished with a hose reel, air foam backpacks and an extinguisher.

If found guilty of mischief by fire, the man could be jailed for up to seven years and fined.