Officials in Delhi have increased the penalty for the use, storage or sale of plastic bags to a maximum of five years jail.
The measure was introduced after a law banning all but the thinnest plastic bags was virtually ignored.
Under the new law, shopkeepers or customers using plastic bags can be fined 100,000 rupees ($3,000) or imprisoned for five years. Officials say that the law will be enforced lightly at first to give people time to adapt but that the penalty will ultimately be up to the courts.
The first country to ban plastic bags was Bangladesh which imposed its ban in 2002. In the same year, Ireland imposed a tax on plastic bags which has reduced consumption by 95%. Other countries, like Rwanda and Bhutan, have also managed to ban plastic bags but Australia has been unable to do so – despite statements in 2007 and early 2008 by the Environment Minister, Peter Garrett, that phasing them out from the end of 2008 was "absolutely critical".