SINGAPORE - From Sunday (April 12), anyone flouting the circuit breaker measures will be fined $300 right away, said Minister for the Environment and Water Resources Masagos Zulkifli on Saturday in a Facebook post.

He said that on Saturday, enforcement officers reported that there were still too many who were not taking the measures seriously.

More than 3,000 written stern warnings were issued, as well as more fines.

"Stiffer penalties are clearly needed," said Mr Masagos.

"From (Sunday), we will no longer issue written warnings. Any offender encountered by our enforcement officers will be asked for (their) particulars immediately," he added.

First-time offenders will be fined $300 and repeat offenders will face higher fines or prosecution in court for egregious cases.

Previously, first-time offenders were issued a written warning, while second-time offenders fined $300, and those nabbed a third time then charged in court.

"The health and safety of Singaporeans are at risk. It is therefore our top priority and collective responsibility," said Mr Masagos, who added that many had shared photos and videos of young and old people not complying with the elevated safe distancing measures.

He also asked members of the public not to send photos that they did not take themselves as some of these would cause enforcement officers to waste time pursuing past events.

On Saturday, the Singapore Food Agency said that all workers engaged in the sale and preparation of food and drinks will be required to wear masks or other forms of physical barriers from Monday.

On Friday, the National Environment Agency (NEA) said that from Sunday, those who do not wear a mask will be turned away at the 39 markets managed by the NEA or NEA-appointed operators.

"The simplest thing everyone can do is to #StayhomeforSG. Let us get through this together," said Mr Masagos.