Countless bloated livestock carcasses were floating across the waterlogged Himalayan region. Many residents, warned to avoid the floodwaters, were rationing water bottles brought by aid workers every few days.

"The chance of cholera, jaundice and leptospirosis spreading are high," said Dr. Swati Jha with the aid group Americares. "The most essential need right now is that of clean water."

The scale of the disaster — described as an "unprecedented catastrophe" by the region's top elected official — has stunned many in India, with newspapers running daily front-page aerial photos of isolated rooftops framed by mud-brown waters.

Most hospitals have been inundated, their diagnostic equipment, CT scanners, operation theaters and ventilators destroyed.

"With our health infrastructure lost, any disease can be catastrophic now. You don't need any plague for mass deaths," said critical care specialist Dr. Javaid Naqashbandi while scribbling out a prescription for treatment of stomach illness on the patient's hand.

The Himalayan region of Kashmir is divided between India and Pakistan, while being claimed by both. And both sides have seen extreme devastation, with tens of thousands of families losing all their possessions.

In Indian Kashmir, more than 200 people were killed and another 287,000 were evacuated after homes, shops and other buildings filled to their rooftops almost two weeks ago.

On the Pakistani side of the border, where flooding hit more than 3,000 villages in both the Kashmir and Punjab regions, at least 328 people have died and 505,254 have been rescued.

New flooding overnight inundated even more villages in eastern Punjab province of Pakistan, and the floodwaters were moving toward the southern Sindh province.

"The rescue and relief efforts are continuing and in full swing," the country's National Disaster Management Authority said in a statement, assuring that food, tents and blankets were being distributed. But many flood victims complained they were still waiting for help. Pakistani news channels showed images Tuesday of police swinging batons as hundreds of flood-affected people attacked trucks and snatched food in the Jhang district of Punjab.

Pakistani doctors have treated at least 123,020 patients in flood-hit areas.

Meanwhile, India was rushing in health workers, sewage pumps, water filters, water purifying tablets and 30 generators to electrify relief camps and field hospitals. Six medical camps and 80 medical teams have already treated more than 53,000 patients, according to the army, which has 30,000 troops on the ground. Aid workers have treated thousands more.

But doctors said the need was vast — and urgent — though they said the cooler mountain temperatures were helping to slow any disease spread.

At least 80 percent of the main city of Srinagar remained under more than 3-4 meters (9-12 feet) of water on Tuesday, with most residents staying in shelters or with relatives on higher ground. As waters began to recede from a few areas, emergency workers started pumping out standing water. But they said it would take several months to remove all the water and clear the debris. Many structures could be in danger of collapse.

Naqashbandi and other doctors working out of the small, private Ahmed Hospital on the outskirts of Srinagar said they already had treated dozens of patients for gastroenteritis, as well as delivering at least 88 babies by cesarean.

In some critical cases, the best they could do was try to keep patients stable, such as 60-year-old Abdul Rashid Wani, who fractured his spine in falling on the second day of the floods while he was taking shelter on a high veranda.

"We thought we had lost our father," said Wani's son, Ishfaq Ahmed, who had helped his father wade through hip-deep waters before flagging down a truck to reach the clinic. "But the hospital has revived him, for now."

Rescue workers were wearing masks to avoid disease contamination. Local aid worker Fayaz Hamed said he visited one submerged neighborhood of Srinagar on Monday night where the air was filled with the smell of rotting flesh.

"It was an overpowering stench, and we saw local residents pulling two bodies (of people) out of the water," Hamed said.

In another area of Srinagar where the Indian army runs a dairy farm with more than 300 cows, only seven survived while the rest were enormously bloated and floating in the floodwaters.

Even dry areas have been affected by the disaster. With everyday municipal services shut down, garbage was piling up, and residents were starting to burn it in huge bonfires that blacked out the sky.

With cellphone services restored only in recent days, many were frantically trying to reach relatives and loved ones who have not been heard from. The government set up a telephone hotline Tuesday to report the missing.

"After the floods, the second disaster came when telecommunications broke down," said teacher Reyaz Qazi, who constantly dialed two telephones simultaneously in hopes of reaching any of his 10 relatives and friends that were missing.

Indian Prime Minister Narendra Modi has asked the nation to skip celebrations for his birthday Wednesday.

"My humble request — do not celebrate my birthday. Instead, dedicate yourselves towards relief work in Jammu and Kashmir through your time and resources," Modi tweeted.