Rescuers at a Moscow water park, where a roof caved in killing at least 25 people, pulled away the last big concrete slabs yesterday but feared more people were trapped under masonry, glass shards and icy water.

Emergencies Minister Sergei Shoigu said 17 more were missing and suggested shoddy building was to blame for the snow-laden roof crashing down on Saturday evening on bathers at the complex of pools and waterslides.

"It's time to stop this chaos and establish control when these kinds of sites are being built," he added, referring to a rush of new construction in the Russian capital.

A day after the collapse, hopes were fading for more people believed to be trapped under debris in below-freezing temperatures.

"We will now be picking through the ruins," a spokesman for the Emergencies Ministry said.

Interfax news agency quoted officials saying the number of unopened lockers at the aqua park hinted at more victims than previously thought.

The horror struck on a busy evening at the popular new playground for middle-class Muscovites, shattering peace in a city already on edge after at least 40 people died in a metro train bombing 10 days ago.

"It's scary just to walk around the city with things exploding," said a Muscovite named Sveta.

"And it's scary to go to these kinds of places, especially since it's not even sabotage - it's just the construction".

The two-year-old Transvaal Park complex won a Moscow city award as a top investment and construction project in 2002, its Web site said.

By yesterday evening, rescuers were pulling down the last concrete roof panels still hanging from the remaining walls of the indoor pool complex.

Mr Shoigu said all roofs of the same type in Moscow were being checked.

Interfax quoted Moscow mayor Yuri Luzhkov saying 25 people had died, but police said the death toll was 26. The Emergencies Ministry said between four and six children had died and at least 110 people were injured.

Russian television said the roof gave way over the children's pool. Luzhkov said 27 children were in hospital, five in critical condition. Doctors said they were suffering from severe wounds, broken bones and shock.

Heat cannons were used to blast the site with warm air in the hope of saving any trapped survivors from freezing to death. Shards of glass cut the feet of sniffer dogs, hampering the search.

More than 420 people were below the section of roof which gave way up to 20 metres above them.

Prosecutors opened a criminal investigation into any possible failure to fulfil "professional obligations".