Hong Kong  - An illegal immigrant has died in hospital after being shot in the head at close range by a police officer in Hong Kong, police said Wednesday.

The unidentified man was shot on Tuesday as he attacked the constable in a city park with a wooden chair, after being challenged to produce his identity papers.

The officer, who had been called to the scene after complaints about the man from residents, used pepper spray and shouted warnings before opening fire on his attacker, police said.

When the illegal immigrant continued to attack him, the officer fired twice, missing with the first shot and inflicting a head wound with the second round, according to a police spokesman.

The incident has raised concerns from some legislators and human- rights advocates, who questioned whether it was necessary for the police officer to use deadly force.

Senior Police Superintendent Wong Chun-chin said that an initial investigation shows that the officer was justified in opening fire because he believed his life was in jeopardy.

"When all the lesser degrees of force have failed and the officer is still under attack, it was the only option left as he felt his life was at threat," he told government-run radio station RTHK.

All police officers in Hong Kong carry guns, but use of firearms is rare in the city of 7 million people, which has a reputation for its safe streets. (dpa)