Held at the Etmauddaula View Point Park on the Yamuna bank, tourism-industry members threatened to go on indefinite hunger strike from November 1, if water was not released in the river.

They said a dry Yamuna was a serious threat to the Taj Mahal whose foundations required constant moisture.

Surendra Sharma, founder president of the Agra Hotels and Restaurants Association said, "There was no water in the river. Only toxic waste and pollutants from upstream cities, industrial effluents were flowing contaminating the dwindling water resources".

The activists also put up a photo exhibition over pollution in the water body at the Goverdhan Hotel to highlight the plight of the river by human waste and industrial pollutants.

At evening, they gathered at the Yamuna ArtiSthal to draw attention to rivers in India facing increasing threats associated with climate change, pollution and haphazard industrial growth.

Jugal Kishore Shrotriya, a temple priest and a young green activist, said the Yamuna, for all practical purposes, was "dead in Agra".

"Only garbage, carcasses and sewer flow. The aquatic life has been decimated. So many plans and schemes to save the river have gone down the drain," he said.

Activists said the free flow of the river has been obstructed by a series of barrages upstream that hold up all the water.

"What reaches Agra is just waste and sewage. The Yamuna Action Plans have made no discernible improvements in water quality. The flow is inadequate. The sewage treatment plants either do not work or are short of resources," Shravan Kumar Singh of the Braj Mandal Heritage Conservation Society said.