The sparkle has returned to the Yamuna River flowing through India's capital of New Delhi, residents say, after decades of filthy and stinking waters, matted with garbage and polluted with toxic effluent from industry.

In a feat that eluded years of government cleanliness efforts, a nationwide lockdown against the coronavirus has brought about the transformation of a river many Hindus consider holy, with a halt in industrial activity since late in March.

Sanjay Gir, a 55-year-old Hindu monk who spends his time on the riverbank, said he could not remember when he had last seen the river so clean.