MUZAFFARABAD, Pakistan (AP) – Rescue teams searching for trapped survivors in the rubble of Pakistan”s worst earthquake scaled back operations Friday, while aid workers held mass burials and rushed to set up tent camps for an estimated 2 million homeless before the harsh Himalayan winter.

With Pakistan”s death toll estimated at more than 35,000, officials said there was virtually no hope of finding more people beneath tens of thousands of collapsed buildings, six days after the disaster. &#34We are all of the view that there is a less than 1 percent chance of survival on the seventh day,&#34 U.N. spokesman Winston Chang said.

In Islamabad, police launched a criminal investigation into the collapse of a 10-story luxury apartment tower that toppled during the 7.6-magnitude quake on Oct. 8, killing at least 40 residents. It was the only structure that collapsed in the Pakistani capital.

&#34We will arrest all those who didn”t perform their duty well,&#34 city police chief Sikandar Hayat said. &#34They might be the builders, contractors or supervisors.&#34

Most of Pakistan”s deaths were in the divided Himalayan region of Kashmir. Snow has started to fall in some areas, and U.N. officials said they fear losing the race against time to bring help. India has reported more than 1,350 deaths in the portion of Kashmir it controls.

Jan Egeland, the U.N. undersecretary-general and emergency relief coordinator, said millions of people urgently needed food, medicine, shelter and blankets.

&#34I fear we are losing the race against the clock in the small villages&#34 cut off by blocked roads, Egeland said during a visit to the devastated town of Muzaffarabad. &#34I”ve never seen such devastation before.&#34

Many exhausted relief workers dealt with the added burden of fasting during the daytime hours for the Muslim holy month of Ramadan.

Maj. Farooq Nasir, an army spokesman in Muzaffarabad, the capital of Pakistan”s portion of Kashmir, said the search and rescue operation had ended. Army officials in Balakot, another hard-hit town, said they were shifting the rubble of collapsed buildings and removing dead bodies.

But Abdul Akbar, a senior official at the Federal Relief Commission, a newly created body to oversee relief operations, said rescue operations were continuing alongside relief work.

Water and electricity was restored to parts of Muzaffarabad, a city of 600,000. Authorities were also working to fix grid stations to bring power back to outlying villages.

The country”s relief commissioner, Maj. Gen. Farooq Ahmad Khan, said Pakistan expected to get 2 million blankets and 100,000 large tents before the onset of winter. He said 200,000 houses had been destroyed.

From daybreak, Pakistani military helicopters and choppers from other countries flew in and out of a sports stadium in Muzaffarabad, where a temporary hospital had been set up. The choppers carried out injured people from remote villages and ferried aid workers to isolated regions.

The U.S. military deployed two MH-53 heavy-lifting Navy helicopters, joining eight Army choppers already running missions into the Pakistani quake zone, where landslides have blocked many roads. It also prepared to send a 36-bed Mobile Army Surgical Hospital, or MASH, from Germany, and a water purification crew.

New Zealand doubled its earthquake aid to US$1 million (euro861,000), as the &#34seriousness of the situation in Kashmir and the northern regions of Pakistan continues to grow,&#34 Aid Minister Marian Hobbs said. Japan dispatched 100 troops and two military transport planes carrying a helicopter and a power-supplying vehicle.

In the stricken Pakistani town of Balakot, dozens of volunteers burrowed into a collapsed school and dug mass graves. They complained that Pakistani soldiers weren”t helping them.

&#34We got 25 bodies of children yesterday and buried them in a mass grave. We got seven more today,&#34 said volunteer Sayed Ahmad Hussain, 35.

&#34We still expect miracles,&#34 Hussain said. &#34But the bodies we pulled out were in bad shape … they are now decomposing.&#34

A relief team from Britain-based Plan International flew a helicopter carrying water, juice and milk to villages in the Mansehra district of North West Frontier Province and said people were hungry and panicking.