Police say four violent criminals are behind bars after a series of arrests in the north. Part-time cab driver Zhou Wen, 38, wanted in connection with the murders of several women since June, was arrested last Friday in Anshan, Liaoning province. Dubbed the 'taxi monster' by the Nanjing-based Jiangnan Times, Zhou wrote of his crimes, including the exact location of the bodies, in a diary he kept with him. He is said to have picked up his victims late at night while driving his taxi and strangled them with rope, dumping the bodies in remote rural areas or in sewers. Described as introverted and quiet, Zhou has served two separate sentences for rape, and murder and theft. He was sentenced to two years' imprisonment at a labour camp in 1981 for rape. In 1988 he was sentenced to 14 years' jail for rape, murder and robbery but was released after serving 11 years. He confessed to the crimes, saying that he kept an exact record of each attack in his diary to remind him of where the bodies were if he was arrested. He was also quoted as saying he was motivated to commit the crimes by his hatred of women. Officers in neighbouring Hebei province have arrested three principal members of a gang which has committed more than 100 crimes in seven provinces in the past decade. All three have confessed to the crimes. On October 23 in Qinhuangdao, Hebei, the gang members shot one bank customer dead and injured another as they stole more than 200,000 yuan (HK$188,000). In November last year, they allegedly held a female bank customer at gunpoint in Qinhuangdao, robbing her of 32,000 yuan. The two gang leaders, Li Jianying and Wang Hongwei, were caught in Heilongjiang province while the third, Gao Shan, was arrested in Tangshan, Hebei. The Qianlong News website says formal prosecutions will begin when investigations are complete.