Starting today, the sixth day of the implementation of a month-long circuit breaker measures, Singapore will impose a S$300 fine for any related offence.

According to the republic's Minister for the Environment and Water Resources, Masagos Zulkifli, "there are still too many people not taking the circuit breaker measures seriously.

"We issued more than 3,000 stern warnings today, and more fines! Stiffer penalties are clearly needed," he wrote on his Facebook page Saturday.

From today, Masagos said, enforcement officers will no longer issue written warnings.

The minister said any offender encountered by enforcement officers will be asked for particulars immediately, and will face a S$300 fine for the first offence while repeat offenders will face higher fines, or prosecution in court for egregious cases.

On the first day, more than 7,000 written advisories were issued to members of the public who breached the circuit breaker measures, mostly in hawker centres and markets.

To further safeguard public health, Masagos noted that the ministry has made it mandatory for all food handlers and wet market stallholders to wear masks.

"This will be effective from 13 April. All visitors to wet markets will need to wear masks from today.

"Those who do not will not be allowed to enter the 40 markets managed by National Environment Agency (NEA) or NEA-appointed operators," he said.

The agency is a statutory board under the Ministry of the Environment and Water Resources.

-- BERNAMA