SINGAPORE - It would have been so easy for physical education teacher Khairil Anwar Tahir to dismiss the commotion he noticed in Bedok North Road on Nov 27 as none of his business.

But when the 39-year-old spotted an elderly man hitting passing vehicles with a hammer, he knew he had to do something.

Concerned that someone would be hurt, Mr Khairil called out to the man, who is believed to be of unsound mind, and tried to distract him.

But he appeared to be in a daze, said Mr Khairil.

The teacher then decided to call the police. Minutes later, police officers tackled the man to the ground and disarmed him. Mr Khairil also helped the officers restrain the man.

The incident was caught on video and it went viral.

Mr Khairil said he could not ignore the incident, adding: "What if everyone thought someone else had called the police? If I didn't do it, it could have been the case that nobody would do it."

On Monday (Dec 2), he was presented with the public spiritedness award at Bedok Police Division.

Commander of the division, Deputy Assistant Commissioner Julius Lim, commended the actions of Mr Khairil and the officers involved.

"Mr Khairil displayed courage and civic duty when he helped to subdue the subject to restore law and order.

"His example reminds us that the maintenance of rule of law in Singapore involves not just the police, but everyday Singaporeans too, stepping forward to work hand in hand with police officers to keep our community safe and secure."

On Nov 27, Mr Khairil had been on his way home to Woodlands from his parents' flat in Chai Chee at about 4pm when he encountered a traffic jam along Bedok North Road.

As he inched forward on his motorcycle, he spotted the man hitting passing vehicles with a hammer. He knew he had to stop the man from hurting himself and others.

Leaving his motorcycle by the side of the road, Mr Khairil approached him and tried to engage the man.

Within minutes, he was joined by officers from Bedok North Neighbourhood Police Centre and the Public Transport Security Command (TransCom).

In the group was Sergeant Lee Wei Liang, 23, the officer seen in the video tackling the man to the ground.

"He was distracted and I was confident that I could neutralise the threat," Sgt Lee said of his calculated move.

Sgt Lee was able to restrain the man with the help of a fellow officer - 20-year-old Special Constabulary Sgt Quinnlan Zaini Hassan - Mr Khairil and others.

They were also joined by off-duty police officer Wong Cheuk Kay, 25, who was on his way to the Singapore Institute of Technology in Tampines.

Sgt Wong, who is from Marina Bay Neighbourhood Police Centre, stopped his car at the side of the road when he noticed the commotion.

He directed traffic and spoke to the drivers of the vehicles that the elderly man had damaged with the hammer.

"Some of the drivers (whose cars were damaged) were agitated, so I stepped in to try to calm them down and let them know that the police were coming," said Sgt Wong.

A day after the incident, the elderly man was charged with committing a rash act that endangered the lives or the safety of others.