Since early this month, more popular beachfronts at East Coast Park have been segmented by the National Parks Board (NParks) to control crowds. NParks also temporarily closes sections when they get too crowded.

In a Facebook post on Tuesday, Minister for the Environment and Water Resources Masagos Zulkifli said the authorities will be stepping up enforcement efforts to ensure that people continue to comply with restrictions under phase two of the economy's reopening.

This comes on the back of multiple instances where people were found to be violating rules, said Mr Masagos.

For instance, the beaches at East Coast Park and Sentosa were "extremely crowded" at the weekend, he noted.

Safe distancing ambassadors and enforcement officers encountered many groups of more than 10 people, including extended families and friends congregating, with a good number who did not wear masks despite being reminded to, saying that they were eating or drinking.

"I have been concerned that some complacency may be setting in, at a time when we must keep our guard up... Extended exposure to one another without masks and in packed crowds places those involved and others around them at greater risk of contracting the Covid-19 virus," Mr Masagos wrote.

Breaches will be taken seriously, he said.

This week, 18 people will be charged in court for gathering at a place of residence for social reasons during the circuit breaker, while another group of 10 were charged yesterday for holding a social gathering at a fitness corner during phase two of Singapore's reopening.

"These actions are not acceptable and a clear violation of the safe distancing measures. We take such breaches seriously because they can potentially lead to the formation of large clusters," Mr Masagos said, urging Singaporeans to continue to remain socially responsible.

For instance, they should wear a mask at all times except when eating, drinking or exercising, and should keep within a group of no more than five. They should also not mix with other groups at parks, beaches and other public spaces, he added.

"We are still in the midst of a long battle with the Covid-19 pandemic. We must be mindful and continue being vigilant. This is critical, for us to protect one another."