BENGALURU: Farmers battling drought in India's southern state of Karnataka began a day-long strike on Friday to protest against the sharing of water from a river that also runs through the neighbouring state of Tamil Nadu.

Police urged calm with all schools and public places staying shut, as thousands of farmers and trade union members held rallies after protests began this week in the tech hub of Bengaluru, against an order from the Supreme Court to share the waters.

"We will not let water from our river enter into the other state at a time when our farmlands are barren," said T. Ramanujan, the leader of a farmers' union in Karnataka.

With millions of farmers dependent on the river Cauvery for irrigation in both states, the dispute over sharing its waters has been one of the long-standing legal battles.

In August the Tamil Nadu government approached the Supreme Court, requesting its intervention, while Karnataka argued that it had inadequate water in its reservoirs due to low rainfall.

Street protests began this week after the court directed Karnataka to release 5,000 cusecs of river water to Tamil Nadu for 15 days this month. A cusec is a volume equivalent to one cubic foot, or 28 cubic litres, per second.

Protesters in Bengaluru chanted "ours, ours, Cauvery is ours," slogans and called for police and government officials to join the protest

Scores of people and some children from distressed districts carried placards with signs that said "We will give our blood but not water."

The government of Tamil Nadu says Karnataka had failed to manage the river and it must limit over-consumption of the shared resource.

"I have sown seeds but the ground is dry due to scanty rainfall and now we have shortage of supply from Cauvery river," said S. Kumar, a 48-year-old farmer in the state's district of Pudukkottai. "Small farmers are struggling this year."

The Cauvery originates in the Karnataka region of Talakaveri and flows through Tamil Nadu before entering the Bay of Bengal.

Officials at an industry body in Karnataka said over 60% of manufacturing plants adhered to the call for strike, a decision that cost them about four billion Indian rupees (over $48 million).

"Nevertheless, we readily accept our losses because we accept that water is crucial for both sustaining life and food production," said Ramesh Chandra Lahoti, President at Federation of Karnataka Chambers of Commerce and Industry.