The Centre for Science and Environment, a city-based NGO, has accused Union minister for petroleum and natural gas Ram Naik for the CNG crisis in the city. CSE chairman Anil Agarwal said the crisis had been built up slowly and deliberately over the last six months. Mr Agarwal also alleged that Indraprastha Gas Limited, the city's sole supplier of CNG, was also responsible in creating the crisis as it did not come up with sufficient CNG daughter booster stations in the last six months.