Massive flooding in the Philippines set off by a tropical storm over the weekend has left at least 140 dead and prompted quick action from Christian relief groups.

World Vision, one of the largest Christian relief and development organizations in the world, is aiming to meet the urgent needs of 100,000 survivors of the massive flooding in Manila caused by Typhoon Ketsana, which has been compared to America’s Hurricane Katrina.

“Thousands of people have lost all they owned – their food, their clothing, bedding, school items, and kitchen equipment. But their immediate needs are for food and water,” reported World Vision Philippines Humanitarian and Emergency Affairs Director Boy Bersales. “Many have gone without either for hours and hours and the children are especially vulnerable having been trapped in flooded conditions for several days. The city is only now waking up to the massive extent of the devastation."

On Monday, the Philippine government appealed for international help after declaring a "state of calamity" in metropolitan Manila and 25 storm-hit provinces, including many that have not flooded before.

Officials said more than 450,000 people were affected by the storm, including some 115,000 brought to about 200 schools, churches and other evacuation shelters.

"Many of the people who have lost everything are sleeping in schools right now," reported Catholic Relief Services Country Representative Luc Picard. "They're calling this the Katrina of the Philippines."

CRS is currently providing immediate food aid-rice, canned goods, noodles, and vegetable oil-to people who fled their homes following massive flooding in the Philippines island of Luzon.

Staff with humanitarian agency World Vision, meanwhile, have already been distributing relief packs by helicopter, in partnership with the Philippine Coastguard. World Vision is now aiming to target four of the worst affected areas of Manila – Marikina, Cainta, Rizal, Pasig – which are home to thousands of poor settlement homes based near rivers and in low-lying areas.

World Vision is also planning to distribute rice, sardines, cooking oil, water, iodized salt, biscuits and canned meat. Other items include mosquito nets, blankets and kerosene lamps or candles along with hygiene items including soap, laundry soap and women's sanitary items.