More than 1,600 telephone towers have been vandalised in an Indian state where farmers have taken the lead in an increasingly angry campaign against government agriculture reforms, officials said.

The action came as tens of thousands of farmers marked more than a month of protests on major roads leading into the capital, New Delhi, against new market reform laws.

Farmers leaders say the reforms will lead to a takeover of the agriculture business by Indian conglomerates and have called for a boycott of groups such as Reliance, which owns the telecom towers, and Adani.

Farm union leaders have however denied any role in the guerrilla action against the telecom towers in Punjab state, India's agricultural heartland.

The towers had power supplies and fibre cables cut while some had their generators stolen, officials said.

A source close to Jio, Reliance's mobile phone enterprise, said more than 1,400 towers had been vandalised up to Sunday. A telecoms industry official said at least 150 more were damaged Monday.

Videos showing Jio employees being chased from towers have been widely shared on social media. Reliance, which is owned by Asia's richest person, Mukesh Ambani, has not commented on the vandalism. But mobile phone services have been affected in Punjab which has 9,000 towers in all.

Protesters have also blockaded one of Punjab's biggest cooking oil depots owned by Adani subsidiary Fortune in the Punjab city of Amritsar.

Davinder Singh, a farmer who took part in a protest in Amritsar on Monday, said the boycott calls were being increasingly followed. "We are with our farmer brothers who are protesting at the Delhi borders. We appealed to the people to boycott Jio and Adani.

"People have heard us. Many people have cut their Jio connections," he said. Farmers have taken over several kilometres (miles) of key roads leading into Delhi, demanding that the government repeal the new laws.

The government says the changes, that allow farmers to sell their produce on free markets, need to modernise the rural sector, the foundation of the Indian economy, and boost farm incomes. Farmers, who received huge public subsidies, have demanded that the laws be repealed and minimum prices for key produce be guaranteed.

A new round of talks between union leaders and the government is to be held Wednesday. But protesters have vowed to step up their action if there is no breakthrough.