Intensified vehicle checks at Delhi's interstate borders to enforce pollution-control restrictions triggered massive traffic snarls on Monday, leaving commuters stranded for hours as long queues built up on roads connecting the national capital with neighbouring Haryana and Uttar Pradesh.

Heavy congestion was reported at several entry points, including the Delhi-Gurugram, Delhi-Noida, Delhi-Ghaziabad, Delhi-Sonipat and Delhi-Najafgarh borders, as enforcement teams checked vehicles for compliance with the prescribed emission standards.

The Delhi-Gurugram border witnessed particularly heavy congestion, with traffic on NH-48 remaining backed up for several kilometres near the Sirhaul toll plaza. The snarls also affected the main carriageway and service roads.

Similar traffic jams were reported near Noida and Ghaziabad, where vehicles were stopped during checks to ensure compliance with the restrictions.

At the Aya Nagar border, Delhi Traffic Police and Transport Department enforcement teams intensified checking and turned back vehicles that did not meet the prescribed BS-VI emission standards.

Senior Delhi Traffic Police officers said all borders, under different ranges, were following the pollution-control guidelines, adding that vehicles below the BS-VI standards were being sent back. Challans were also being issued for violations and incomplete vehicle documents, they said.

The restrictions came into effect on November 1 as part of the winter pollution-control measures. Under the new arrangement, petrol and diesel vehicles registered outside Delhi that do not comply with BS-VI emission standards are barred from entering the national capital.

Electric and CNG vehicles, along with BS-VI-compliant vehicles, have been exempted from the restrictions.

The enforcement is being jointly carried out by the Delhi Environment and Transport departments and the traffic police at several entry points, including Rajokri on NH-48, DND Flyway, Ghazipur, Singhu, Tikri and Badarpur.

The measures aim to curb vehicular emissions during the winter months, when air pollution levels in the national capital typically rise.