Singapore's immigration officers have performed well under pressure, even as more checks have been progressively rolled out to contain the outbreak of the Wuhan coronavirus, Law and Home Affairs Minister K. Shanmugam said yesterday.

"We have had to put in additional measures to check travel history and symptoms... (though) we don't have that much additional manpower, that is the truth.

"But systems are running smoothly and I have to say that our officers have performed exceptionally well in taking on the load."

He was visiting Woodlands Checkpoint yesterday to observe temperature screening measures introduced by the Immigration and Checkpoints Authority (ICA) on Jan 24 and to lend his support.

He also addressed Facebook rumours that ICA officers working at Customs and customer service counters at Singapore's airports and land checkpoints had allegedly been instructed not to wear masks.

He said that ICA officers, like many other front-line government officers, have been given the same protocols, one of which is to stay away from work if unwell.

"I think there has been a misunderstanding. If you are not well, then you shouldn't even be there," Mr Shanmugam said. But if they were at work and felt they needed to wear a mask, they could do so.

Lester Wong