BEIJING -- The Ministry of Public Security is planning a nationwide crackdown on violent crimes involving guns, drugs, homicide, assaults on police officers and obstruction of law enforcement.

The crackdown was revealed Friday at a teleconference for criminal investigation departments. Vice Public Security Minister Li Wei described the action as "a necessary choice" to ensure social security, stability and the authority of the police.

The plan follows a recent surge of violent crimes, including a man who shot dead four people, including two police officers, earlier this month in Hebei Province, north China.

It's not immediately clear when the crackdown will start or how long it will last.

"Police departments at all levels should see to that every violent crime case is dealt with and violent criminals are punished in accordance with the law," Li said, calling for severe penalties for obstructing law enforcement.

The ministry also urged police to step up security at public venues such as schools, kindergartens, hospitals, shopping malls, cinemas, subways and buses, with armed patrol and more checks.