Davos: Ahead of the keenly-watched India visit of Barack Obama, rights group Amnesty International on Thursday asked Prime Minister Narendra Modi to raise the issue of Bhopal gas tragedy during his meeting with the US President in India.

"People have been waiting for justice and their rights for decades. The impact of the tragedy is still visible and the toxic chemicals are still stored in a room there. Health hazards are being passed on to the next generation. It has been the biggest ever industrial disaster in terms of human impact and the issue still remains an overhang," Amnesty International Secretary General Salil Shetty said here.

"Modi must bring it to the attention of Obama," Shetty told PTI in an interview here on the sidelines of WEF Annual Meeting.

Shetty said that it was strange that US-based Dow Chemicals says that it was different from Union Carbide, while the fact remains they had acquired them with all their assets and liabilities.

"A political will is a must to ensure justice for the people who were affected by the tragedy," Shetty said, while urging Modi to raise the issue with Obama during his visit to India.

"If you look at how the US took on oil giant BP over the gas leak issue, we understand that a political will can help ensure action against even big corporates on such matters," he said.

"Dow and Union Carbide cannot duck away from this issue and Obama must be told about it. We are anyway talking about only peanuts when it comes to compensation for the victims vis-a-vis the huge revenues of an industrial giant like Dow," he said.