"For the three days we have recorded dip in the metro footfall," Delhi Metro spokesman Anuj Dayal told IANS.
But while passenger traffic didn't fall steeply Saturday and Sunday, it plunged from the usual 16 lakh to 14.22 lakh Monday, he said.
Delhi Metro, the city's lifeline, daily ferries nearly 1.8 million passengers over 2,700 trips.
Since the weekend, nine metro stations -- Pragati Maidan, Mandi House, Barakhamba Road, Rajiv Chowk, Khan Market, Race Course, Udyog Bhawan, Central Secretariat and Patel Chowk -- have been shut.
This follows a request from police who want to prevent people protesting against the gang-rape of a young woman Dec 16 from reaching the city centre.
The closure of the metro stations -- particularly Rajiv Chowk, the capital's busiest station -- has inconvenienced thousands across the city.
Both Rajiv Chowk in Connaught Place and Central Secretariat are also inter-change stations.
Metro trains are not halting at seven of these stations.
But they halt at Rajiv Chowk and Central Secretariat to enable passengers to switch trains.
"With Rajiv Chowk station closed, I found it difficult to attend mass yesterday (Monday) at Sacred Heart Cathedral," said Sylvia Paul, a young woman from east Delhi.
Software professional Gerogina Daniel said: "I'm not able to visit my relative and friends for Christmas as key metro stations are closed. And autos are demanding exorbitant fares."