“Unless more access to Myanmar is granted to allow aid to flow more quickly, a second catastrophe could result,” Elizabeth Byrs, Spokesperson for the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) warned.

The hardest-hit areas of Yangon and Irrawaddy delta are experiencing heavy rains, further impeding aid efforts. The junta must open at least an air or sea corridor to channel aid in large quantities as quickly as possible, he said.

The Myanmar government has granted only 34 new visas to UN personnel, Byrs said, adding “this is not enough to respond to a disaster of this magnitude”.

Meanwhile, the UN refugee agency announced that more than 40 tons of its shelter supplies including plastic sheets, blankets, kitchen sets and tents have reached Yangon, Myanmar’s largest city, in the past 24 hours.

Half of these items were airlifted in from Dubai. “Our staff are at the Yangon airport to claim the items for immediate dispatch to areas affected by the cyclone,” said Jennifer Pagonis, spokesperson for the UN High Commissioner for Refugees (UNHCR).

The other half of the supplies were driven overland from the Thai-Myanmar border in two trucks, carrying items from UNHCR’s stockpiles for refugee camps along the Thai border, in a two-day journey through heavy rains.

The agency immediately handed the items, expected to benefit 10,000 people, to non-governmental and community-based organisations to be distributed in the hardest-hit areas.

UNHCR expects another round of supplies including 4,500 plastic sheets, 17,000 blankets, some 1,500 kitchen sets and 75 mosquito nets, which arrived in the agency’s first airlift from Dubai last weekend to be rushed to the outskirts of Yangon and to Bogale and Laputto in the Irrawaddy delta.

The UN World Food Programme (WFP) has sent more than 360 metric tons of food aid, of which 175 tons has been distributed.

For its part, the UN World Health Organisation (WHO) has flown in medical supplies for tens of thousands of people and is monitoring for communicable disease outbreaks in the wake of the cyclone.

The agency said that while diarrhoea and dysentery cases have been reported, there have been no confirmed cases of cholera. Immediate efforts are centering on caring and treating the injured and preventing communicable diseases.

WHO personnel, including 11 international staff, are operating in Myanmar, and eight emergency health kits each able to treat 10,000 people for three months have been delivered to the affected areas.