A woman has been detained for three days in Shanghai after admitting to police she had choked an elderly neighbour, causing her to faint, in an argument over household waste on Thursday. It came after the city last week mobilised tens of thousands of volunteers – most of them pensioners – to help with its new rubbish and recycling system by advising neighbours on how to dispose of their waste the right way. Under the new system introduced on July 1, individuals risk penalties of between 50 and 200 yuan (US$7.3 to US$29) if they do not sort their rubbish properly. Businesses and organisations face fines of between 50,000 and 500,000 yuan (US$7,000 to US$70,000). On Thursday, the 33-year-old woman surnamed Ye had ignored the suggestion of a volunteer about separating kitchen waste from her other rubbish, news portal Thepaper.cn reported, citing police. Ye choked the woman until she fainted, then left her in the street, the report said. The victim was taken to hospital and spent a night under observation before going home the next day. Ye surrendered to police on Friday evening and spent three days in detention. In the first week of the waste classification system, Shanghai’s municipal urban management authority issued 199 punishment notices, state news agency Xinhua reported. Shanghai shows city way in war on waste Officials said about 60 per cent of the fines were imposed in residential blocks and public venues where there were not enough bins to allow rubbish to be sorted properly. The rest of the penalties were issued to individuals or companies who had flouted the rules.