Women gather salvaged belongings from their flooded home after monsoon rains, in the Qambar Shahdadkot district of Sindh Province, of Pakistan Tuesday. More than 1,300 people have been killed and millions have lost their homes in flooding caused by unusually heavy monsoon rains in Pakistan this year that many experts have blamed on climate change. Associated Press

Fareed Khan

ISLAMABAD — In flood-stricken Pakistan where an unprecedented monsoon season has killed hundreds of people, the rains now threaten a famed archeological site dating back 4,500 years, the site’s chief official said Tuesday.

The ruins of Mohenjo Daro — located in southern Sindh province near the Indus River and a UNESCO World Heritage Site — are considered among the best preserved urban settlements in South Asia. They were discovered in 1922 and to this day, mystery surrounds the disappearance of its civilization, which coincided with those of ancient Egypt and Mesopotamia.

The swelling waters of the Indus, a major river in this part of the world, have wreaked havoc as heavy rains and massive flooding unleashed devastation across much of Pakistan. At least 1,325 people have been killed and millions have lost their homes in the surging waters, with many experts blaming the unusually heavy monsoon rains on climate change.

The flooding has not directly hit Mohenjo Daro but the record-breaking rains have inflicted damage on the ruins of the ancient city, said Ahsan Abbasi, the site's curator.

“Several big walls, which were built nearly 5,000 years ago, have collapsed because of the monsoon rains," Abbasi told The Associated Press.

He said dozens of construction workers under the supervision of archaeologists have started the repair work. Abbasi did not give an estimated cost of the damages at Mohenjo Daro.

The site's landmark “Buddhist stupa" — a large hemispherical structure associated with worship, meditation and burial — remains intact, Abbasi said. But the downpour has damaged some outer walls and also some larger walls separating individual rooms or chambers.

Abbasi said the civilization at Mohenjo Daro, also known as “Mound of the Dead" in the local Sindhi language, built an elaborate drainage system, which has been critical in flooding in the past.

Though the floods have touched all of Pakistan, the Sindh province has been among the worst hit.

On Monday, army engineers made a second cut into an embankment at Lake Manchar, Pakistan's largest freshwater lake, to release rising waters in hopes of saving the nearby city of Sehwan from major flooding.

The water from the lake has already inundated dozens of nearby villages, forcing hundreds of families to leave their mudbrick homes in a hurry, many fleeing in panic.

Meanwhile, rescue operations continued Tuesday with troops and volunteers using helicopters and boats to get those stranded out of the flooded areas and to nearest relief camps. Tens of thousands of people are already living in such camps, and thousands more have taken shelter on roadsides on higher ground.

Ghulam Sabir, 52, from the outskirts of Sehwan, said Tuesday that he left his home three days ago after authorities told them to evacuate.

“I took my family members with me and came to this ... safer place," said Sabir, staying by the roadside where he has set up camp. He echoed complaints of several other villagers — that no government help had reached them yet.

Sabir said he did not know whether his home had collapsed or not.

Prime Minister Shahbaz Sharif urged Pakistanis in televised remarks Tuesday to generously donate to flood victims, most of whom are relying on government help to survive. Sharif has also repeatedly asked the international community to send more aid to the flood victims. He insisted that Pakistan is facing a climate-change-induced tragedy.

In a statement Tuesday, the U.N. refugee agency said it handed over thousands of tents and other emergency items to the Sindh government, meant for those affected by the flooded areas in the province.

Multiple experts say that since 1959, Pakistan has emitted about 0.4% of heat-trapping carbon dioxide, compared to 21.5% by the United States and 16.4% by China. Last week, U.N. Secretary-General Antonio Guterres also called on the world to stop “sleepwalking” through the crisis. He plans to visit flood-hit areas on Sept. 9.

According to Pakistani officials, Guterres will travel to Sindh but it's unclear whether he will visit the archaeological site.