The death toll from the deadly blaze at Tai Po's Wang Fuk Court has risen to 151 as officers discovered more bodies in their search, with some found burned beyond recognition.

The force began its search at the last two of the seven fire-ravaged buildings – Wang Sun House and Wang Cheong House – on Monday.

New Territories North regional commander Lam Man-han said the structures of the two blocks were not "entirely safe", but officers were racing against time to enter units that were secure.

Eight bodies were discovered at the flats, corridors and stairwells of Wang Cheong House, Lam said, with three of them previously found by emergency personnel.

"Wang Cheong House was the first building to catch fire, and it took a longer time for the blaze to be put out. The conditions there were extremely bad. It was a scene of devastation. Some of the bodies were incomplete, or even burned to ashes," she said.

More than 30 people were still unaccounted for, according to chief superintendent Tsang Shuk-yin.

"As some of the bodies had been burned to ashes, we do not rule out the possibility of not being able to recover all missing persons," said Tsang, who appeared emotional.