The Philippines has appealed for international aid after the worst flooding to hit the capital Manila in more than 40 years. A month's rain fell in just 12 hours which turned roads into rivers. More than 70 people are known to have been killed. Hundreds of people are still thought to be trapped by flood waters which at one stage affected most of Manila. Rescue efforts are now focusing on the east of the city. The government says more than four thousand people have been rescued so far and a quarter of a million people have been displaced by flooding and by mud-slides caused by typhoon Ketsana. Helicopters and river boats are being deployed across the city. In northern Philippines, 24 provinces have also been declared a state of calamity.