A man went on a rampage in a police station in Shanghai on Tuesday, stabbing five officers to death and wounding another five before he was stopped, local media reported.

The suspect, an unemployed 28-year-old man, sought revenge for an interrogation last year in which he was suspected of bicycle theft, the official Xinhua news agency said.

He stabbed a security guard at Shanghai's Zhabei district police station, where the interrogation had been conducted, set a fire at its gate and then barged inside wielding a knife, it reported.

"All-out efforts are being made to save the five injured," the Oriental Morning Post said on its website (www.dfdaily.com).

One was in critical condition, Xinhua said.

Media reports identified the man as a Beijing resident.

China, which is preparing for an influx of foreign visitors for the Beijing Olympics starting August 8, has been at pains to boost security.