Commuters wade through waist-deep floodwaters after the arrival of Tropical Storm Ketsana (locally known as Ondoy) on Saturday in Manila. Nearly a normal month's worth of rain fell in just six hours, triggering the worst flooding in 42 years in the Philippine capital. (Bullit Marquez/Associated Press)At least 72 people are dead or missing after Tropical Storm Ketsana hit the Philippines on Saturday, officials said.

Ketsana produced the worst flooding in more than 42 years in the capital city, Manila, and nearby provinces.

Defence Secretary Gilbert Teodoro said more than 4,000 people had to be rescued, including many left clinging to each other on roofs and on top of a passenger bus.

The rescue effort, which involved soldiers, police and civilian volunteers, was to expand Sunday as the weather began to clear and floodwaters started to recede.

In Manila, the storm forced commuters to wade through waist-deep floodwaters. Scores of vehicles were stalled in flooded streets around the capital.

President Gloria Macapagal Arroyo appeared on television to urge people to be patient as they wait for rescuers.

"I am calling on our countrymen, especially residents of metro Manila and other provinces in the path of the typhoon, to please stay calm, follow the instructions of local officials and civil defence authorities," she said.

The government has declared a "state of calamity" in metropolitan Manila and 25 storm-hit provinces.

With files from The Associated Press