Thousands return to city after flood work

But thousands more who fled from the waters that inundated neighbouring towns complained about the shortage of food and water as they camped in a vast Muslim graveyard on a hill nearby.

Hordes of people ran after vehicles distributing food and water near the graveyard, a chaotic effort that left many flood survivors – especially the old and infirm – with nothing. Some drank rainwater pooled on the ground.

Authorities said they were trying to provide food and shelter to the hundreds of thousands of people camped out on the hill in Makli. But as in other areas of the country, the scale of the disaster has overwhelmed both local capacity and the international partners trying to help.

"We are trying to set up a tent city in different parts of Makli so that the distribution (of aid) could be organised," said Hadi Baksh, a disaster management official in Sindh province.

The floods started about a month ago in the north west after extremely heavy monsoon rains and have slowly surged south along the Indus River, devastating towns and farmland. More than 1,600 people have died and 17 million are affected by the floods.

Authorities struggled to save Thatta on Sunday, building new levees with clay and stone across a major road to hold back floodwaters that inundated the nearby town of Sujawal. Many of Sujawal's 250,000 residents had already fled, but the water damaged houses, schools and other buildings.

Most of Thatta's 350,000 residents had also fled in recent days but began to return to the city as the danger passed, said Baksh.

Thatta, which is about 75 miles (125km) south-east of the major coastal city of Karachi, contains several well-known mosques, including one built by Shah Jahan, the ruler of the Mughal Empire in India in the 1600s.

Water levels are beginning to drop in Sindh as the floodwaters flow down the Indus River into the Arabian Sea, said Baksh.