Residents are getting help at eight medical camps and 35 door-to-door teams of health workers have been sent into the area to provide rehydration salts and basic hygiene information awareness to residents, they said.

"Thirteen people have died in my area after drinking contaminated water," local mayor Muhammad Waheed Chauhdry told AFP.

People started falling ill with gastroenteritis at the start of the week, residents said, adding that sewage seeping into water supplies was to blame.

The government of Punjab government, of which Lahore is the capital, has ordered the replacement of old water pipes and suspended a sanitation official, district administrator Khalid Sultan told AFP.

More than 1,000 people have reported stomach problems at the medical camps, he said.

Almost one third of Pakistan's 150 million population has no access to safe drinking water, while 76 million live without any sanitation facilities, according to the government.

President Pervez Musharraf said on Tuesday that Pakistan aimed to provide clean drinking water for the entire population by 2008 by setting up new purification plants.