Survivors are complaining that aid is simply not reaching those that need it

The official death toll for Burma's cyclone disaster has jumped to almost 78,000 people, with nearly 56,000 missing, according to state TV.

The numbers are nearly double those released on Thursday, raising fears the final human toll may be enormous.

The Red Cross is seeking more than $50m (£26m) in aid to help survivors of the storm which struck on 2-3 May.

Foreign aid agencies are frustrated at the slow progress of aid to areas worst hit, especially in the Irrawaddy Delta.

A BBC reporter in the delta this week saw little sign of official help and foreign aid workers have been barred from the area.

We are certainly going to see a further aggravation of the situation, further destitution among an already very hard-hit population Thomas Gurtner Red Cross director of programmes and co-ordination

Heavy rain has been lashing the region, compounding the misery of survivors of Cyclone Nargis.

The UN Humanitarian Co-ordinator, John Holmes, is due to visit Rangoon, Burma's main city, on Sunday in a bid to persuade the military government to grant more access to UN relief workers and expand its aid effort.

Earlier, the EU's top aid official, Louis Michel, was denied permission to visit the delta region. He said he was given no explanation why disaster emergency experts were being refused visas.

However, Burma - also known as Myanmar - has promised to take foreign diplomats on a tour of the region this weekend.

'Beggars for miles'

Previously, Burma was giving a toll of 43,000 dead and 28,000 missing while the Red Cross and United Nations had estimated a death toll above 100,000.