SINGAPORE - Some travellers who entered Singapore via Woodlands Checkpoint on the morning of Feb 22 were delayed at immigration after a panic alarm caused the authorities to lock down the bus hall.

The incident, which took place at around 8.30am, resulted in queues that stretched from the bus hall on the second floor to the first floor of the building.

A number of travellers shared photos on Facebook of them stuck in long, snaking queues. They also said that officers on the ground were searching for Myanmar passport holders.

One traveller, who wanted to be known only as Mr Kim, was heading to work in Singapore when he was caught in the lockdown.

The 34-year-old chef told The Straits Times: “I was stuck in the queue for around 25 minutes... there was a huge crowd.”

Another traveller who spoke to Shin Min Daily News said he was about to scan his passport at the kiosk when the alarm went off, and several officers came out to look for Myanmar nationals.

The traveller, who wanted to be known only as Mr Lim, said he later saw four men and a woman being taken away by officers for questioning.

An Immigration and Checkpoints Authority spokesman said the panic alarm was activated at around 8.30am. The authorities stopped operations at the immigration area while officers investigated the situation.

The lockdown affected those who entered via the bus hall, but not those who entered in vehicles such as cars or motorcycles, said the spokesman. He added that clearance at the affected area resumed at about 9am.

“After investigations, it was established that there had been no incident of concern,” said the spokesman, who did not say whether any arrest was made.

Operations were stopped temporarily during the lockdown to enable investigations to be carried out smoothly without compromising public safety and security, he added.