Thousands of Indian farmers on Tuesday escalated protests to revoke controversial new agricultural laws, clashing with police and storming key landmarks in New Delhi to pressure Prime Minister Narendra Modi.

The farmers, who have camped at various border points around the capital for two months, had permission to demonstrate after the completion of an annual military parade to mark Republic Day, a major public holiday in India. But many gathered early in the day and broke through barricades on the outskirts of the city, prompting police to deploy tear gas in some areas.

The Samyukt Kisan Morcha, an umbrella organization of several dozen farm groups leading the protests, issued a statement late Tuesday calling off the remainder of the tractor parade in Delhi and criticizing the "anti-social elements” that "had infiltrated the otherwise peaceful movement.” The police also blamed the protesters for deviating from the agreed routes and attempting to enter the heart of the capital where Parliament and other government buildings are located.