The Centre on Thursday said that construction work on the metro rail projects in Mumbai, Hyderabad, Chennai, Kolkata and Kochi would commence within two years. Replying to a question in Rajya Sabha, Union urban development minister Jaipal Reddy said: "The metro projects for Mumbai, Hyderabad, Chennai, Kolkata and Kochi are in different stages of approval. The government's effort is to expedite the process.