The section was slated to be open September 2010, a month before the Commonwealth Games next year.

Malhotra said that a bridge had collapsed in Laxmi Nagar earlier and the investigations into that incident were still on.

Delhi Mayor Kanwar Sain, who visited Sunday's accident site, said: 'The Delhi Metro projects are going at a fast pace and the quality of work is being compromised. An enquiry is necessary.'

However, Delhi Chief Minister Dikshit denied allegations that the bridge collapsed due to work being done in haste for the Games.

'It is worrying that this is the second incident in the past few months. It is a lesson for everyone. DMRC carries its work independently and has a good past record. I don't think it was due to the pressure of Commonwealth Games that the incident happened. There is no pressure that could lead to the collapse,' Dikshit said.