Fifty more people complained of nausea and difficulty in breathing and were treated in local hospitals, an official of the disaster management department said. All of them were discharged by Friday.

As a precautionary measure, the civic authorities evacuated around 3,500 people living in the slums around the dumping ground.

'They will be permitted to return only after the army and civic experts complete their investigations,' a civic official added.

Apart from the army, teams of the disaster management department, fire brigade, health department are at the site which has been cordoned off by the police.

There were no casualties in the incident. The remaining one million people in the township were not affected at all, a police official said.