The Delhi government has notified that the entry of buses, barring CNG, BSVI diesel and electric ones will be regulated in the capital, if restrictions under the final stage of the Centre's air pollution control plan are invoked.

Stage IV is the final stage of the Graded Response Action Plan (GRAP).

"Entry of all buses, including All India Tourist buses/ Contract Carriage buses/ State Transport Buses or holding any other kind of permit into Delhi from other states except CNG / Electric or BSVI diesel buses will be restricted as and when GRAP IV invokes.

"The above mentioned restrictions shall stand automatically applicable, as and when GRAP - IV is invoked from the date of issuance of this order in Delhi Gazette, and if the GRAP IV is revoked the said restrictions stand terminated automatically, no separate order will be issued," an official gazette notification said.

Last month, the Delhi government directed that all buses entering the national capital from Haryana will have to be run on electricity, CNG or BS-VI diesel.

Buses entering from the NCR regions of Uttar Pradesh and Rajasthan also need to follow these norms.

The city government's transport department said all buses entering Delhi from any city or town in Haryana, Rajasthan and Uttar Pradesh from July 1 will only be those that run on electricity, CNG and BS-VI diesel.

The Commission for Air Quality Management (CAQM) in National Capital Region and Adjoining Area, a statutory body responsible for formulating strategies to combat pollution in the region, had on November 18 asked Delhi and NCR states to revoke all emergency measures, under which only CNG, electric and BS VI-compliant vehicles from other states are allowed to enter Delhi, with exemptions granted to those involved in essential services.

The air quality across the city worsened on Wednesday morning and was recorded in the very poor category.

The city's Air Quality Index stood at 394 at 9.05 am on Wednesday, up from 365 on Tuesday.

The GRAP for the NCR has been classified under four different stages of adverse air quality in Delhi viz. Stage – I 'poor' (AQI 201 – 300), Stage – II 'very poor (AQI 301-400), Stage – III 'severe' (AQI 401-450) and Stage – IV 'severe +' (AQI >450), respectively.

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