(Adds U.N. aid, paragraphs 11-13)

By Nizam Ahmed

DHAKA, Nov 20 (Reuters) - Relief workers and the Bangladesh military on Tuesday reached the last remaining pockets of the country devastated by a cyclone that killed nearly 3,500 people along the Bay of Bengal.

It has taken some five days to gain access to the hardest hit areas in an operation involving helicopters, planes and boats, as well as thousands of ground troops and aid workers.

Two U.S. C-130 transport aircraft and two American naval vessels were poised to join the effort.

"We have reinforced relief efforts by adding more helicopters and cargo planes to fly food, medicine, water and other essential goods to the survivors," said an army official.

But food supplies were still woefully inadequate.

"Hundreds of hands go up to grab just one food packet. This is a mad rush but a tragic reality on the entire coastline ravaged by the cyclone," said a relief operator in the Patuakhali district.

The Category Four cyclone struck late on Thursday with 250 kph (155 mph) winds that whipped up a five-metre (16-foot) tidal surge.

The disaster was the worst in the impoverished country of 140 million since 1991 when a cyclone and storm surge killed around 143,000 people.

"Food, clothes and shelter are needed immediately for the survivors who are resilient and are trying to start life anew," said Louis-Georges Arsenault, of the U.N. children's fund, UNICEF, after visiting some of the worst hit areas.

The army-backed interim government said supplies would increase in coming weeks once $142 million in promised emergency relief from international donors and the king of Saudi Arabia starts rolling in.

UN SENDS AID

The United Nations said it had authorised a first disbursement of $8.75 million to support the relief effort, drawn from its Central Emergency Response Fund, set up two years ago to get aid to disaster zones more quickly.

"I hope this ... will enable some important and immediate life-saving needs to be met," U.N. emergency relief coordinator John Holmes said in a statement issued in Geneva.

The world body was distributing 208 tonnes of high-energy biscuits, shelter materials for 18,000 households and 240,000 packets of water-purifying powder for 48,000 families, it said.

Officials in the affected areas, inhabited mainly by fishermen but also some farmers, said a shortage of drinking water and medicine had caused diarrhoea outbreaks in many places.

The navy and coastguard had started work on rebuilding homes, defence sources said, and troops were helping civil officials to remove uprooted trees blocking highways.

A local official in Patuakhali said children had started returning to class, but some teachers held classes in the open because thousands of school buildings had been destroyed.

Director of U.S. Foreign Assistance and USAID Administrator Henrietta H. Fore arrived in Dhaka on Tuesday to assess the damage and the need for assistance.

"President (George W.) Bush has asked me to inform you that both civilian and military assistance would come in the next days for the cyclone victims in Bangladesh," she told reporters.

"The two naval ships with greater capacity for evacuation are expected to arrive in Bangladesh on Nov. 23 and Nov. 27."

Washington has pledged $2.1 million in emergency aid.

The 6,000-sq km (2,320-sq mile) Bangladesh portion of the world heritage Sundarbans mangrove forests, home to more than 400 Royal Bengal tigers, was devastated, foresters said. (Additional reporting by Anis Ahmed, Ruma Paul, Serajul Islam Quadir, Masud Karim and Azad Majumder, and by Stephanie Nebehay in Geneva; Editing by Tim Pearce) (For more information on humanitarian crises and issues visit www.alertnet.org)

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