Rescue workers search the rubble of a building collapse in Bangladesh, hoping to find survivors more than 24 hours after the structure came down.

At least 228 people have died so far - most of them female workers. Many more are still trapped.

The Rana Plaza building complex housed factories supplying Western clothes retailers, 30km outside the capital Dhaka.

Rescue workers pulled at least seven people out of the building alive on Thursday, but most of the families here have had to identify their relatives from amongst rows of corpses.

At the association which represents clothing manufacturers and exporters, more than 1000 people turned up to protest - pelting the office with stones and clashing with police.

Authorities say the owner of the collapsed building - a local politician - was told about dangerous cracks the day before the collapse.

While a bank in the building was closed, factories told their workers there was no danger.