SINGAPORE - All pupils and staff of Punggol Primary School will undergo mandatory swab tests on Thursday (July 29) and Friday.

This comes after a new cluster linked to a cleaner at Punggol Primary School was identified on Tuesday and grew to 12 cases on Thursday, according to the Ministry of Health.

Meanwhile, the school will switch to home-based learning from Thursday to Aug 6.

In response to queries from The Straits Times, the Ministry of Education (MOE) on Wednesday night gave details of six cases in the cluster.

It said one teacher and two pupils have tested positive. The teacher is not a close contact of the pupils, and investigations are under way to see if the cases are linked.

Another two contract cleaners and one non-teaching staff from the school have tested positive for Covid-19. All of them had not been in close contact with pupils and teachers.

MOE said: "All close contacts of confirmed cases have been placed under quarantine order or leave of absence."

Punggol Primary School has also been thoroughly cleaned and disinfected.

The education ministry said it will continue to monitor the situation closely, and work with the school and parents to ensure the well-being of staff and pupils.

MOE said: "Students and staff should also seek medical attention immediately if they feel unwell. Continue practising good personal hygiene and adhere to safe management measures."

The first case of school-based transmission was on May 21, when an 11-year-old pupil at Anglo-Chinese School (Junior) tested positive for Covid-19 after his classmate had done so on May 19.