Indian authorities have significantly increased security at three main protest sites outside New Delhi’s border, adding iron spikes, steel barricades and hundreds of riot police in an attempt to stop tens of thousands of demonstrating farmers from entering the Indian capital.

In Ghazipur, one of the protest sites, iron nails have been embedded along the main highway. Cemented barricades were wrapped with coils of barbed wire as government forces guarded what looked like a security fortress.

Images of the barricades were widely shared on social media, with many comparing them to heavily-militarised border fences.

Since late November, thousands of farmers have camped on the outskirts of the city, braving the cold and rain, in a largely peaceful protest against new agriculture laws they say will devastate their income and make farmers vulnerable to corporate greed.

The months-long protests have rattled Prime Minister Narendra Modi’s government, which says the new laws will benefit farmers and boost production through private investment.

Devender Singh, a protesting farmer from Uttar Pradesh state, said the new security arrangements were intended to scare them away. “But farmers won’t run away so easily,” he said.

The heavy security presence and added measures come a week after the protests turned violent when farmers on tractors, horse-back and on foot broke through barricades and clashed with police to enter the city.

They stormed New Delhi’s landmark Red Fort in a brief but dramatic takeover on January 26, India’s Republic Day.

One protester died and several hundred police officers were injured in the clashes. Officials have not said how many farmers were injured.

The situation remains tense, with authorities extending an internet shutdown at the protest sites.

Rahul Gandhi, senior leader of the main opposition Congress party, condemned the new measures, tweeting: “Build bridges, not walls!”

On Monday, Twitter temporarily suspended the account of one of the protesting farmers’ groups, Kisan Ekta Morcha, but restored it hours later after online outrage.

The social media platform said in a statement it acted upon a “valid legal request” issued by an authority, adding it may withhold access to “certain content” if it receives a “properly scoped request from an authorised entity”.

Samyukta Kisan Morcha, or United Farmers Front, a coalition of farmers spearheading the protests, said the measures are “part of multiple attacks being organised by the government, police and administration”.

The group said it will hold a three-hour nationwide strike on Saturday. Multiple rounds of talks between the government and the farmers have failed to end the deadlock.