SHANGHAI, July 2 (Xinhua) -- The Chinese Ministry of Public Security (MPS) has sent its condolence to the families of five policemen stabbed to death by a Beijing man on Tuesday, according to the Shanghai Municipal Public Security Bureau website on Wednesday.

    The message of condolence was sent around 6 p.m. Tuesday to the Shanghai municipal bureau to extend its sympathy and solicitude to the families.

    The suspect, Yang Jia, stabbed a security guard at a police branch in Shanghai's Zhabei District at 9:40 a.m. with a knife. He then started a fire at the gate of the facility.

    Yang, 28, then charged into the building and attacked nine officers with his knife. Five police died of their injuries, authorities said.

    The jobless man was then apprehended by police and detained. The reasons for his attack was still under investigation, sources with the municipal bureau said.