SINGAPORE - Two motorcyclists who were riding against the flow of traffic on the Seletar Expressway were stopped by police officers who were in the process of dealing with another motorcyclist who had been caught speeding.

The riders, who were all issued with summonses, were nabbed while The Straits Times was riding along with Traffic Police during a covert enforcement exercise against errant motorists on Wednesday (Oct 23).

There were 34 violations detected during the operation for offences such as speeding, using a mobile phone while driving and failing to obey traffic lights.

The first driver issued a summons while The Straits Times was present had been seen driving a van along the Tampines Expressway while using his phone.

His driver's licence was verified and he was notified of the possible offence he had committed.

The police said drivers were stopped if they were holding the phone and seen to be texting or calling while the vehicle was moving.

In some cases, the driver's phone is seized and the SIM card returned to them.

Two motorists were also stopped for speeding on the SLE and Mandai Road.

The officers, who were dressed in black, conducted the operation from 10am to 4pm.

The number of speeding-related and drink-driving accidents in the first half of 2019 decreased compared with the same period last year.

But fatal accidents involving motorcyclists increased 24.1 per cent to 36 in the first half of 2019 from 29 in the same period in 2018.

The top three traffic offences detected during covert operations held between January and September this year were speeding, using mobile communication devices while driving and failure to keep left.

"Road safety is a shared responsibility. (The Traffic Police) would like to urge all motorists to adopt good road sense to keep Singapore roads safer for everyone," the police said.