As air quality turned severe again in the national capital, Delhi Environment Minister Gopal Rai on Friday directed agencies and departments concerned to ensure strict implementation of curbs on polluting vehicles and check the increasing incidents of biomass burning, reported news agency PTI.

Recent data shows that vehicular emissions account for about 25-30 per cent of the capital's air pollution. Though stubble burning has reduced, biomass burning at different locations in Delhi-NCR is responsible for 21 per cent of Delhi air pollution, Rai told reporters, reported PTI.