SINGAPORE - A bespectacled man who had locked himself in a flat at Block 1, Marsiling Drive, while believed to be armed with a knife, was arrested for committing a rash act on Wednesday (Sept 6) afternoon.

The Straits Times understands that the 49-year-old man had allegedly threatened a Malaysian couple - tenants who had been living at the seventh-floor unit since 2014 - who were trying to move out of the flat.

The Singapore Civil Defence Force (SCDF) was alerted to the incident at 1.30pm.

"A man had locked himself in a room," the SCDF said, adding that as liquefied petroleum gas (LPG) was detected, it evacuated neighbouring units and set up a water jet.

SCDF also deployed an airbag on the ground floor and Disaster and Rescue Team (Dart) rappellers were on standby as a precautionary measure.

​Police say the man had barricaded himself in the unit and was subsequently arrested for committing a rash act.

The tenant, food court stall operator Lee Tong Way, said the man was the flat owner who stayed with them. He said the man had been paranoid about being caught by the police and was not of a sound mind recently.

On Monday, he had brandished a butter knife to the tenants, telling them it was for self-defence.

"We decided to move away for good, but he did not like the idea that we were leaving and thought we were betraying him," said Mr Lee, 44.

He called the police when the man, whom they knew as Chen, locked himself in the room where Mr Lee had kept some of his money.

A neighbour living five doors down on the same floor, who wanted to be known only as Madam Bartha, 67, told The Straits Times that she saw the frightened couple at her door at around 1pm.

She invited them to wait at her home, and gave them food and water, until police took the man away at around 4.30pm.

The housewife said: "I do not know who the man is but I know the couple, who are very friendly people. They were completely scared and it was only right for me to help them."

Madam Sufahati Rufiee, 77, a part-time teacher, who also lives on the same floor, said: "It first started at around 12 plus, when I heard a lot of voices and then policemen and firemen shuffling past the corridor. There was a long stand-off but thankfully the couple who lived there are safe."

Police investigations are ongoing.