GENEVA/LONDON/YANGOON (Agencies) - Hungry crowds of survivors stormed reopened shops in Myanmar's devastated Irrawaddy delta, as the United Nations urged the ruling military junta to grant visas to international relief workers. Cyclone Nargis destroyed 80 per cent of buildings in the worst-hit parts of Myanmar, aid workers for Doctors without Borders (MSF) and the UN said Wednesday. Paul Risley, a spokesman for the UN World Food Programme in Bangkok, said that aid workers had reported "fist fights are breaking out" after a few shops had reopened. Little aid has reached the area since the cyclone hit the country last weekend. The UN refugee agency said that 22 tonnes of emergency relief supplies are waiting at the border as the military authorities have yet to allow them to enter the country. "We are working closely with the Myanmar authorities to get our relief supplies into Myanmar by road from Thailand," said Janet Lim, director of the UN High Commissioner for Refugees' Asia Pacific bureau. The country's secretive ruling generals have given a UN aid plane permission to land carrying 25 tonnes of aid, while neighbouring India and Thailand have also sent aid flights. And a Chinese plane carrying 60 tonnes of aid has landed in the main city Yangoon, Chinese state media report. Thousands of shell-shocked survivors emerged, desperate for food and water after trekking for days through flood waters littered with the bodies of the dead. The death toll in Myanmar cyclone may top 100,000 and 95pc of the buildings have been destroyed in the delta area there, Shari Villarosa, the US charge d'affaires in the Myanmar capital, said in a conference call that "there may well be over 100,000 deaths in the delta area," citing an international non-government organisation she would not name. The MSF chief coordinator on the ground in Myanmar appealed for the authorities to let aid workers and supplies already standing by enter the country. "Our first assessments show that, in the Daala and Twantey zones, south of Yangon, home to 300,000 inhabitants, 80pc of buildings have been destroyed," said a statement posted on the group's website. The UN's WFP has begun to distribute food in and around Rangoon. But so far the generals have resisted calls to waive visa requirements from aid workers, instead appointing Deputy Foreign Minister Maung Myint to oversee visa applications. Meanwhile, international charity Save the Children said an estimated 40pc of the dead or missing from the cyclone are believed to be children. The agency said its workers on the ground believe that the casualty toll could be "much higher" than the official toll of 22,980 dead and one million homeless, comparing it to the 2004 Asian tsunami. The storm surge in many parts of the country's low-lying delta region was reportedly as high as 25 feet in places, and as the delta is a very flat area it is expected that many, many people drowned. After days of criticism aimed at the secretive generals who have ruled the Myanmar for nearly half a century - and who have hesitated to let in foreign relief workers - the United Nations said experts were on the way. "We hope that this spirit of openness will continue," said spokeswoman Elisabeth Byrs in Switzerland, announcing that a plane with 25 tonnes of aid was en route from Italy with UN disaster relief experts on board. Meanwhile, Slovakia pledged $95,000 in emergency aid, the Foreign Ministry said. The Spanish Foreign Ministry said Madrid will send a plane loaded with 13 tonnes of medicine, tents, drinkable water and other emergency relief aid to Myanmar. Taiwan pledged $200,000 in emergency relief to Myanmar, and is sending a team to help with rescue efforts. Japan said it was more than doubling its emergency aid to Myanmar as humanitarian concerns mount, adding it would send another $343,000 in blankets, portable water tanks, sleeping mats and other supplies.