The Delhi Police on Friday raided two popular food joints in the city's iconic Khan Market and recovered over 100 oxygen concentrators, used for treatment of Covid patients, officials said. According to the police, 96 oxygen concentrators were recovered from Khan Chacha Restaurant, and nine were seized from Town Hall restaurant in Khan Market. These concentrators were being sold in the black market, said police. Both outlets are linked to Navneet Kalra, the alleged black marketer of oxygen concentrators in Delhi. The police said it wants to question the businessman.