HONG KONG, May 5 -- A local man was shot dead by the police in the wee hours Monday when he attempted to attack his wife, the police said.

The man, 21, armed with a retractable knife, took a security guard as the hostage as he tried to attack his wife at about 3 a.m. Monday morning in a residential building in Lam Tin where they live.

Two officers fired three shots at the man whom they had already warned, Senior Superintendent Eugene Yue from the Kowloon East regional crime unit told the local media.

The man was confirmed dead at the scene and it was still unknown which part of the man's body was hit, Yue said, adding that there are strict rules on using firearms by the police.

Yue said CCTV footage from the building's lobby was being retrieved to aid the investigation and the coroner's court will probe into the case.