In the central Philippines, nearly all houses in Tacloban in Leyte province with a population of about 220,000, were toppled and casualties were feared to be massive, a disaster official said.
"Almost all houses were destroyed, many are totally damaged. Only a few houses are left standing, but with partial damages," Major Rey Balido, a spokesman for the national disaster agency said.
"Our disaster officials can't give a number on casualties yet, the communication lines are down," Major Balido said.
"But I asked our teams to send us even a crude body count, they are just using a satellite phone and the signal is poor."
The typhoon has triggered landslides and floods and knocked out power and communications across a number of islands.
The Philippine president said the death toll from Typhoon Haiyan could be lower than initially thought, but that many areas remain cut off.
Satellite images of the Philippines before and after Typhoon Haiyan struck show how the storm flattened whole communities.
British typhoon survivor says home nearly collapsed on him and his family