A man took control of a woman's car at knifepoint in Upper Bukit Timah Road yesterday and then crashed the car into a lamp post near Woodlands Checkpoint about 15 minutes later.
The 43-year-old man then got into a stand-off with officers near the checkpoint and was arrested later for armed robbery and other offences.
A witness told The Straits Times yesterday that the man crashed the car into others in the queue near the checkpoint around 1.45pm.
The Malaysian, who gave his name only as Mr Tangarajah, was on his motorcycle waiting to clear Customs when he heard a crash.
"I turned around and saw a red car in an accident with other cars," he said. The driver of the red car made a U-turn and veered off the road, hitting a lamp post, he added.
He said eight to 10 officers approached the car and asked the man to open the door but he refused.
He tried to make a getaway in the vehicle, but was surrounded by officers, said Mr Tangarajah, 38.
The man eventually got out of the car and was later subdued and led away in handcuffs, he said. The stand-off lasted about 20 minutes.
Videos posted online of the incident went viral yesterday afternoon, showing a man wielding a sickle while an officer approached him.
Other clips showed several officers at the scene, with what appeared to be debris and a fallen lamp post on the road.
The officers included those from the auxiliary police and the Immigration and Checkpoints Authority.
Police said the man was suspected of being under the influence of drugs.
Suspected drug paraphernalia, controlled drugs, a knife, an axe and a sickle were found in his possession.
He was arrested for armed robbery, possession of offensive weapons and suspected drug-related offences.
Investigations are ongoing.