Witnesses described the raid as terrifying, with the policemen and about 10 pedestrians diving for cover as bullets flew.

The robbers, wearing surgical masks, entered the bank on the first floor of Siu Hong Court shopping centre about 11.30am.

'One of them guarding the exit of the bank fired a shot towards the ceiling and his accomplice jumped over the counter and snatched about $100,000 from drawers,' Senior Superintendent Albert Kwok Cho-kuen said.

There were more than 20 staff and customers in the bank at the time, he said.

'Bundles of bank notes amounting to between $30,000 and $40,000 were dropped at the exit as the men fled. Their action was prompt and well-planned. They stayed inside the bank for about 15 seconds.' A witness said the robber guarding the exit pointed his pistol at a security guard, Yip Sin-kiu, when she heard the shot and went to check.

A witness said: 'The woman security guard stood motionless outside the bank for seconds and then stepped backwards and ran.' The robbers fled but saw the two policemen when they reached a mezzanine floor. They fired four shots towards the officers at a range of about 15 metres but no one was hit.

The pair ran towards a multi-storey car park. Minutes later, a white Toyota with two men inside left the car park without paying.

Police discovered the getaway car bore a false number plate after they traced the address of the owner and found another white Toyota with the same number in a residential block in Wylie Road, Yau Ma Tei.

A source said the Wylie Road car owner was a senior superintendent.

The pair were described as being in their 30s or 40s and both are about 1.7 metres tall.