He assured that construction would be undertaken on all other Metro Rail corridors only after thorough checking.

The work at this stretch was being undertaken by Gammon India Ltd, a private firm contracted by the DMRC.

Thirty workers were present at the site - most of them from Bihar, Orissa and Uttar Pradesh - at the time of the accident.

Three of the dead have been identified as Anshuman, a site engineer, and construction workers Niranjan and Badan Singh, DMRC spokesman Anuj Dayal said. Three bodies were recovered trapped under the debris which was being removed till late Sunday.

The injured were taken to the All India Institute of Medical Sciences (AIIMS), Safdarjung and Moolchand hospitals.

Construction workers allege that the pillar on which the girder segment was to be hoisted was faulty. Delhi Police have registered a case of negligence against the company.

Said Joint Commissioner of Police (southern range) Ajay Kashyap: 'Our immediate priority is to clear the debris and to carry out rescue operations. We have registered a case of negligence, and technical experts will carry out an inquiry into the matter.'

'The traffic, and power and water supply in the area have been affected following the rescue operation. Debris clearance will take time as the collapsed structure is quite big,' Kashyap said.

Sreedharan said the DMRC was making an effort to remove the debris and open at least one section of the main arterial road that carries traffic to the Nehru Place business district, which was closed to traffic immediately after the pre-dawn accident Sunday.

The Delhi government announced a compensation of Rs.500,000 to the kin of each of the deceased, Rs.200,000 each to those permanently disabled and Rs.50,000 each to those injured. The compensation will be paid by the DMRC.

Delhi's main opposition Bharatiya Janata Party (BJP) leader V.K.Malhotra accused the state government of rushing the Metro project ahead of the Commonwealth Games.

But Dikshit said: 'I don't think it was due to the pressure of the Commonwealth Games that the incident happened. There is no pressure that could lead to the collapse.'

This was the second major accident in the history of Delhi Metro after October 2008, when a launching girder collapsed killing two in Lakshmi Nagar in east Delhi.

Delhi Metro, which began operations in 2002 and has been held up as a model of efficiency, runs 70 trains on various routes and carries over 800,000 people every day.