Singapore has asked gyms and fitness studios to shut until the end of May, and reduced the number of people allowed to gather at restaurants, public venues and meetings and called for offices to let more people work from home after a rise in COVID-19 cases.

The tightened rules take effect from Saturday, May 8, and reduce the number of people allowed to gather to five from eight with households allowed five distinct visitors daily, according to rules announced by the health ministry and updated on the Channel News Asia (CNA) website.

Under the guidelines, only two social gatherings daily are permitted and outdoor classes are capped at 30 people who must be socially distanced. Office staff levels need to be trimmed to 50% from 75%, and for places of worship, congregational singing will be suspended.

The new rules came into effect after a public hospital in Singapore, Tan Tock Seng, reported a COVID-19 cluster last week that included staff and patients with mutant strains. More than 40 cases were noted, and it was the first at a hospital on that scale this year, raising concern of a wider spread.

Singapore earlier this year had eased restrictions on gatherings, increasing to eight from five the number allowed to meet in public spaces and restaurants. It had also recently agreed to a travel bubble with Hong Kong to start May 26.

The country has been widely lauded for a rapid vaccination program and required measures such as wearing masks and social distancing to control the spread of COVID-19 cases.

But the recent spike in cases has led to restrictions on travel, including a bar for now on visitors from India and Thailand, where fresh outbreaks and a surge in cases have stressed healthcare systems.