Children and staff at five more PCF Sparkletots pre-schools have reported symptoms of food poisoning, bringing the total number of cases to 238. The figure includes 16 people from Plan Student Care Centre in Ubi Avenue 1 who reported similar symptoms.

They were all served by Kate's Catering, which has been suspended. Of the affected, 14 remain in hospital and are in stable condition.

The additional five PCF centres affected are the ones at Sengkang Central Block 231, Punggol Coast Block 326, Paya Lebar Block 221 and Toa Payoh Central Blocks 79B and 146A.

Yesterday, PCF chief executive Victor Bay said: "We are taking this matter seriously and our priority remains to ensure that our children receive the necessary medical care and attention, and to provide the relevant support for all affected parties."

Mr Bay added that PCF is in close contact with affected parents and is monitoring the condition of the children."The children who are still in hospital currently are in stable condition, and we look forward to welcoming them back to school eventually."

PCF has made temporary arrangements for in-house cooks to provide meals to the affected pre-schools.

The authorities were notified of the first cluster of cases on March 22, and conducted an inspection of the caterer's premises the same day.

Additional clusters were reported last Monday, prompting the National Environment Agency (NEA) to instruct Kate's Catering to suspend its operations pending investigations by the Agri-Food and Veterinary Authority, the Ministry of Health (MOH) and NEA.

Food handlers were sent for stool screening, and food and environmental samples were taken for testing as part of the investigations. A spokesman for Kate's Catering said it is working with the authorities.

MOH said food poisoning or food-borne illness often causes vomiting and diarrhoea, which may lead to dehydration, especially in young children and the elderly. It is important for affected people to rehydrate by drinking plenty of fluids and seek medical attention if necessary.

The Early Childhood Development Agency is working with the authorities to investigate the outbreak at the pre-schools.

Pasir Ris-Punggol GRC MP Teo Ser Luck told The Straits Times yesterday: "I am very concerned about this issue, especially since this is not the first food-poisoning case to occur this year. A thorough investigation must be conducted, and a good explanation must be given to all parents."

He said PCF is taking all precautions to uphold food hygiene and implement further safety measures.

• Additional reporting by Joy Pang Minle