NEW DELHI, Aug. 7 — Two of the world’s largest multinational companies, Pepsi and Coca Cola, today ratcheted up a long-running campaign in India to prove their soft drinks are safe, as local governments widened a partial ban on their products following a report by an environmental group claiming the sodas contained high levels of pesticide.

The dispute, which first flared in 2003 after the same group accused the companies of using pesticide-laced water, has stoked a fresh media maelstrom here and fanned protests across several regions.

Cans of Coca-Cola were poured down the throats of donkeys in one protest this weekend, while activists from regional political parties smashed cola bottles made by both companies and attacked several shops in Delhi where the drinks were on sale. Protesters in Calcutta burned bottles of Coca-Cola.

On Friday, India’s Supreme Court demanded that Coca-Cola reveal its secret recipe — guarded for the past 120 years — so that the allegations of high pesticide levels could be verified with further tests.