More than 1,300 members of a Mexican indigenous group fell ill with food poisoning after eating cake 'not fit for human consumption' at a Children's Day event.

In total 1,358 people - including at least 200 children - received medical attention after eating cake at a party thrown by humanitarian organization World Vision.

The government of Veracruz, where the incident took place on April 30, said it was investigating the poisoning while World Vision promised to work fully with officials.

At least 200 children were among 1,300 people sickened after eating cake described as 'not fit for human consumption' during a Children's Day event in Mexico

The event, which was thrown for indigenous peoples in the Veracruz region, took place in a local school and was put on by humanitarian organization World Vision

The incident took place at a local school where the cake was served, and shortly afterwards people began complaining of symptoms such as dizziness and vomiting.

Private vans from the Mexican Social Security Institute took the victims to a nearby hospital where the majority of them were given fluids to counter-act the symptoms.

However, some needed intravenous drips after becoming badly ill and two children are reportedly still in a serious condition in hospital.

Children's Day is an annual celebration of youngsters held in Mexico on April 30 each year.

World Vision said it has been involved in Children's Day celebrations for more than 10 years, and is 'deeply concerned' by the poisoning.

Silvia Novoa, director of World Vision Mexico, said: 'We are still working with the authorities to determine the causes of this incident, one that has never happened before.

Medics said most people had to be given oral fluids to counter-act the symptoms, but a few needed IV drips and reports suggested two children are still in hospital

World Vision, which has helped organise Children's Day events for 10 years, said it is 'deeply troubled' by the news and pledged to 'fully cooperate' with investigators

'As an organization, we have worked for more than 10 years to improve the life conditions of these communities in terms of teacher training, drinking water systems, school improvement, nutrition and economic development.

'Our commitment is firm and we will make sure that each child is fully recovered.'

Zenyazen Escobar Garcia, the secretary of Education of Veracruz, said that the incident had been serious and could have been tragic.

World Vision Foundation is a humanitarian organisation working for the children living in Mexico to help them live free of poverty, protected and in sustainable communities.

The Foundation sent a press statement saying that it was extremely concerned about what had happened, and confirming that they were ready to help authorities to find out what caused the poisoning.

The investigation is ongoing.