World Vision says children are bearing the brunt of the worst floods to hit Thailand in 50 years.
The flood waters have so far claimed at least 373 lives and are affecting 26 provinces in the central and north-eastern regions.
Residents in capital Bangkok are stacking sand bags at the doors of their businesses and homes as the waters creep towards the city centre.
Some suburbs are already deluged and the city centre has been warned of flood waters of at least 1.5 metres high if the barriers break.
Parts of Bangkok’s second airport, Don Muang, have already been deluged, jeopardising the national flood response which has its headquarters based there.
According to World Vision, more than 600,000 children have been affected by the floods.
It is distributing emergency food and relief items, and has opened two child-safe spaces to support children distressed by the rising waters.
The Christian development agency said it was concerned about the risk of water borne diseases.
World Vision Thailand's National Director, Chitra Thumborisuth, said: "We want to meet the basic humanitarian needs of the most vulnerable communities and children who have not yet received support from local authorities.
“We are deeply concerned by the impact of the disaster, especially on the hundreds of thousands of children.
"Houses are muddy and soiled with debris. Families need to replace their basic household appliances and utensils not to mention find a way of salvaging their livelihoods.”
World Vision said it plans to stay after the flood waters have receded to help rehabilitate affected communities.
Children hit by severe flooding in Thailand
Published 26 October 2011