From today, anyone flouting the circuit breaker measures will be fined $300 right away, said Minister for the Environment and Water Resources Masagos Zulkifli yesterday.
This means no more warnings will be issued beforehand.
The move comes as all beaches were closed yesterday to curb the spread of the coronavirus and rules to get Singaporeans to stay home were tightened further.
Enforcement officers reported that there were still too many who were not taking the measures seriously, said Mr Masagos.
More than 3,000 stern warnings and 50 fines were issued yesterday, said the Ministry of the Environment and Water Resources.
On Friday, more than 2,900 stern warnings and 40 fines were issued. In total, more than 6,200 stern warnings and 90 fines have been issued since April 7, said the ministry.
It also said police assistance was required in about 20 cases where members of the public were not cooperative when asked to comply with the safe distancing measures.
Two men are being investigated for offences under the Liquor Control Act and Covid-19 (Temporary Measures) Act 2020 for drinking at an HDB void deck in Marsiling Road at about 1.20am yesterday.
"Stiffer penalties are clearly needed," said Mr Masagos of people flouting safe distancing rules. "From (today), we will no longer issue written warnings. Any offender encountered by our enforcement officers will be asked for (their) particulars immediately."
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 were fined $300, and those nabbed a third time were 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 in photos that they did not take themselves as some of these would cause enforcement officers to waste time pursuing past events.
"The simplest thing everyone can do is to #StayhomeforSG. Let us get through this together," said Mr Masagos.
In announcing the closure of beaches, National Development Minister Lawrence Wong said the Government has to do what is right and necessary to protect Singaporeans in a public health crisis.
"In theory, we could keep most places open, so long as safe distancing measures are strictly adhered to. But increasingly, we see that this is hard to achieve. So tougher measures are necessary," said Mr Wong, who is co-chair of the multi-ministry task force against the coronavirus.
Mr Wong reiterated that Singaporeans must drastically reduce contact with others for the circuit breaker to be effective, even as he acknowledged that there are people who "genuinely find it hard to adjust".
"I continue to receive a lot of feedback on the circuit breaker measures... Some say that it's only a partial lockdown and ask for a full lockdown, which they think will be more effective," he said.
"Others say the current measures are already too restrictive and causing mental and social problems for themselves and their families... We will do our best to support them."
He added: "We have to sustain this effort not just for a few days but till the end of the month at least. So stay home as much as possible."