Ingredients thought to have caused a mass outbreak of food poisoning on Saturday at a Siem Reap province event organised by the NGO World Vision were seized yesterday and sent to Phnom Penh to undergo tests.

A crowd of more than 700 people, mainly comprising schoolchildren, attended the event in Chi Kraeng district, which focused on raising awareness about child labour. But free snacks organised by the NGO – a baguette filled with meat and pickles – left the majority unwell.

Siem Reap Provincial Governor Khem Bunsung said 542 people, including 364 children, had fallen ill. He added that most had been quickly discharged from hospital, with just 30 people remaining at health centres yesterday afternoon.

However, Um Sareth, the head of a health centre in Pongro Loeu commune, said the real number was much higher, with more than 800 people reporting symptoms of food poisoning.

Soeun Sen, chief of Siem Reap’s anti-economic crimes police unit, said officials yesterday ordered the temporary closure of the bakery that supplied the bread.