A large piece of the ceiling of a flat in Block 17, Kwai Chung Estate, fell down early on Sunday morning. Mr Lee said he was worried the Housing Authority was neglecting the maintenance and refurbishment of older estates once they were lined up for redevelopment.

He and fellow Democratic Party and Kwai Chung District Board member Sin Chung-kai met authority officials yesterday morning.

They asked the authority to speed up reconstruction plans for ageing public housing estates.

They also asked it to reserve vacant flats for Kwai Chung Estate residents who might have to move out of their homes for safety.

More than 60 public housing residents turned up at authority headquarters with a petition, demanding that redevelopment be speeded up.

Surveyors began safety checks on all flats in Kwai Chung Estate yesterday. The examination is expected to be finished by June 26.

The authority announced earlier that the tenants on the top floor of the two blocks believed to be in danger of concrete falls - about 50 flats - could decide whether to be temporarily or permanently relocated.

The authority, however, declined to confirm that the concrete collapse last Sunday was related to construction work on the roof.

Residents have complained that the work destroyed the water-resistant coating of the roof causing leakage and concrete falls.

The tenants of the flat where the ceiling gave way refused to accept a flat allocated to them, saying they were being treated unfairly.

The Chan family has accused the authority of giving them a flat in Tai Wo Hau when there are vacant flats in the same block.