Delhi switch to CNG

One of the most polluted cities in the world -- the Indian capital, Delhi -- has introduced laws aimed at reducing carbon emissions from road traffic.

Starting today, all public transport vehicles -- including buses, taxis and motorised rickshaws -- will have to be converted from diesel to compressed natural gas, or CNG.

The measures were imposed by the Indian Supreme Court which, after protests, conceded that six months' grace would be given to operators provided they had already placed an order for the conversion to CNG.

Offenders risk having their vehicle impounded. The BBC Delhi correspondent says that, because today and tomorrow are public holidays, the full impact of the measures on public transport won't become apparent until Tuesday.

From the newsroom of the BBC World Service