BEIJING, Jan. 1 -- Shanghai Metro passengers are still eating and drinking in the city's subway cars despite a new rule against doing so.

Eastday.com reported on Jan 1 that subway staff can only dissuade passengers from eating and drinking in trains but cannot forcibly stop them because the rule, which went into effect on Jan 1, was not a legal regulation.

The ban on eating and drinking in the metro network aroused debate when Shanghai lawmakers failed to include the ban in the new Shanghai Metro Management regulations.

The city's metro operator, Shanghai Shentong Metro Group, has long asked subway riders not to eat and drink on trains, but without much success.

Cities like Hong Kong and Singapore do not allow eating in their transit systems. On the Chinese mainland, Guangzhou banned eating in subway cars in 2009, followed by Xi'an in 2011.