In view of the deteriorating air quality in the national capital and neighbouring cities, the Delhi Metro Wednesday pressed into service 21 additional trains on its network that will provide 812 additional number of trips daily, officials said.

The move came on a day when the 17.8-km Shiv Vihar-Trilokpuri-Sanjay Lake section of the Pink Line was opened for passengers, that will have three interchange facilities. "Keeping in view the worsening of air quality in Delhi-NCR, the Delhi Metro has introduced 21 additional number of trains on its network on October 31, which will provide 812 additional number of trips per day," a Delhi Metro Rail Corporation (DMRC) spokesperson said.