A resident holds to a rope as he passes a flooded area on Talon 4 in Las Piñas. (Photo by ALI VICOY)

MANILA, September 28, 2009 (AFP) - The Philippine government faced an angry backlash Monday over flooding that claimed at least 140 lives, with residents voicing frustration at the pace of rescue efforts.

With some people still stranded on the upper floors of their homes more than 48 hours after the flooding began, the government admitted it was not prepared for the disaster but insisted it was not to blame.

Defending the government's actions, officials repeated President Gloria Arroyo's statement that more rain fell on Manila and surrounding areas in Saturday's deluge than on New Orleans when Hurricane Katrina hit there in 2005.

However, for many the disaster revealed the divisions that separate the city's rich and poor, and problems with planning and development in the city.

"Why is it that rich villages get help first?" said Bobby Santillosa, head of a neighborhood-based disaster-response team in Bagong Silangan, a low-income northern Manila neighborhood.

The community leader saw 29 neighbors drown in the flooding sparked by tropical storm Ketsana, when more than a month of rain fell in less than nine hours.

"They were already dead when rescuers arrived," he added.

A woman who refused to give her name told AFP that the government response was too little too late, as police rescued her elderly parents from a rooftop in a poor neighbourhood near the bank of the Pasig River.

"Help was too slow coming. We've been up here since Saturday and we had not eaten anything since then," she said.

Parts of the city of 12 million people were under up to 20 feet (six meters) of water, leaving at least 140 people dead and forcing nearly half a million from their homes across Manila and surrounding provinces.

Bayani Fernando, the Metropolitan Manila Development Authority chief who is responsible for flood control in the capital, said that among the major factors in the flood were poor city planning, illegal structures and simple geography.

"Our problem is we live where we should never have lived," he said.

Manila, which like most of the country lies on the Pacific typhoon belt, is bisected by the Pasig and Marikina rivers whose waters connect Manila Bay to the west with a huge lake, Laguna de Bay, to the east.

Some areas of the city lie below sea level, sit on silt and rely on pumps to keep the water out, while the eastern district of Marikina, ground zero of the disaster, is a valley surrounded by the Sierra Madre mountain range.

He said obstructions, either caused by squatters putting up illegal structures or rich landowners encroaching on land such as riverbanks that allow natural drainage, should be removed.

"If we want to stop this, we have to remove all the things that are obstructing the waters," Fernando said.