The use of ultra-thin plastic bags is still widespread five years after the introduction of a national ban aimed to reduce pollution and save energy, a new report revealed on Thursday.

In April, the National Development and Reform Commission, China's top economic planning agency, said the use of plastic bags had plunged since regulations were brought in on June 1, 2008.

Use in large supermarkets and shopping malls has decreased by more than two-thirds, the NDRC said, while retail outlets saved the equivalent of 1 million metric tons of plastic by handing out 67 billion fewer bags.