SENDAI, Japan (Reuters) - Heavy snow blanketed Japan's devastated northeast Wednesday, hindering rescue workers and adding to the woes of the few, mainly elderly, residents who remained in the area worst hit by last week's massive earthquake and tsunami. In some parts of Sendai city, firefighters and relief teams sifted through mounds of rubble, hoping to find any sign of life in water-logged wastelands where homes and factories once stood. But, as they did in most other towns, rescuers just pulled out body after body, which they wrapped in brightly coloured blankets and lined up neatly against the grey, grim landscape. "The strong smell of bodies and the dirty seawater make search extremely difficult," said Yin Guanghui, a member of a Chinese rescue team working in the battered town of Ofunato. "Powerful waves in the tsunami would repeatedly hit houses in the area. Anyone trapped under the debris would be drown in no time, without any chance to survive." Japanese media said at least two people were pulled alive from the rubble, more than 72 hours after the earthquake and tsunami struck. But rescue officials said the snow weakened what little chance they had of finding any more survivors. "Snow has just come down in a blanket. Visibility is just 40 meters," said Patrick Fuller of the International Red Cross Federation from what remained of Otsuchi, a fishing hamlet. "People are still working, the army is out here. But the fire service has taken off because they are worried they won't get back to their base because of the snow." In Rikuzentakata, rescue workers used diggers to clear streets strewn with debris congealed by mud and now covered in snow. The fire department said more than 80pc of the city was flooded, and the situation was likely to get worse due to the snowfall. Officials estimate Friday's earthquake and tsunami have killed at least 10,000 people, with thousands missing. The meteorology agency said temperatures could drop as low as -2 Celsius in Sendai Wednesday. Broadcaster NHK offered tips on how to stay warm - wrap your trunk in newspaper and cling film - and how to boil water using empty food cans and candles. Rescuers said their main concern was for the elderly, who make up the majority of the scores of people packed into shelters. "They are having a very tough time of it," said Fuller. Meanwhile, Japan's Emperor Akihito in a rare television address Wednesday expressed deep concern over the escalating nuclear crisis and said he prayed for people's safety after last week's quake-tsunami disaster. The 77-year-old, who has the great respect of many Japanese, admitted in the pre-recorded comments that the country still did not know how many people had died in the March 11 twin disasters. He thanked emergency personnel - both from Japan and abroad - for their efforts to locate the many missing and help survivors battling difficult conditions including increasingly cold temperatures in the affected zone. "The number of people killed is increasing day-by-day and we do not know how many people hav fallen victim," Akihito said. "I pray for the safety of as many people as possible.