Emergency workers in Pakistan's Punjab province used drones to find people stranded on rooftops by massive floods as the government expanded its rescue operation with more than 900,000 evacuated, officials said Monday.

The Pakistan Meteorological Department warned of more heavy rain in Punjab’s flood-hit districts and elsewhere in the country, where weeks of above-normal rainfall and the release of huge volumes of water from dams in neighboring India last week caused rivers to overflow into low-lying regions.

Authorities say Punjab, the country's most populous province, is facing its biggest floods on record.

In Multan and Jhang districts, residents on Monday waded through floodwaters carrying their belongings to roadsides and higher ground.

They said they had waited for rescuers before crossing on their own nearly 5-foot-deep (1.5-meter-deep) water to reach safety, while many others remained stranded.

"We have evacuated our homes and taken our families and animals to safe places. Floodwater is approaching fast, most of the people have already evacuated the area and people are building embankments in front of their streets and houses”, villager Muhammad Javed said.

Since last week, rescuers, backed by the military and emergency services, have evacuated more than 900,000 people from more than 3,100 flood-hit villages, said Irfan Ali Kathia, director general of the Punjab Disaster Management Authority.

“In some places we have 10 feet (3 meters) high floodwater and in some six feet (1.8 meters). So far, we have evacuated hundreds of people," rescue worker Jamshaid Iqbal said.

More than 600,000 farm animals were also moved to safety.

The Punjab government said drones were deployed this week in Multan, Jhang and other districts.

The deluge has swamped Narowal, Sialkot and Kasur districts while entire villages have been submerged in Jhang and Multan.

Authorities in Punjab say they had set up more than 1,000 relief camps, but government figures show that only about 36,550 evacuees are housed in them.

It is unclear where the vast majority were staying.

AP Video by Jahanzaib