Indian farmer unions have scrapped next week's planned march on parliament against new agricultural laws, as rifts emerge after violent protests in New Delhi left one person dead and almost 400 police injured.

Thousands of farmers running riot on tractors on Tuesday was a major embarrassment for the government, but also for the 42 unions representing the farmers, who have mostly condemned the violence.

Late Wednesday their main umbrella group said that the planned march on parliament on February 1 -- when the government presents the budget -- had been pushed back, although nationwide rallies were still planned on Sunday.

Farmers have been camped outside New Delhi for two months demanding that the new laws be scrapped, because they fear they will leave them at the mercy of big corporations.

Two roads blocked by the protestors for weeks were cleared late Wednesday as two unions withdrew from the protest, each blaming other groups for Tuesday's events.

"I am so ashamed and sad about (Tuesday) that I announce an end to our 58-day-long sit-in protest at this (Delhi) border," one union leader, Bhanu Pratap Singh, announced on Wednesday.

Another protest camp on the outskirts of the Indian capital was also cleared overnight, with local police denying claims that they had emptied the site using force.

At another site, Ghazipur, there was an increased police presence on Thursday.

The main protest camp at the Singhu border crossing remained packed with protestors, although some have left and the mood was sombre.

"Yes, many people left as they were disappointed about Tuesday but we are still here, and hope they will be back," Baljinder Singh, 32, from the northern state of Punjab, told AFP on Wednesday.

"It was a minor blip. The government planned it and changed the direction of our tractor march, and they intentionally directed us towards the city centre," Baljinder added.

Delhi police have signalled a tough line, saying they are studying footage and using face-recognition technology to identify and arrest those involved in the violence.

On Wednesday police commissioner SN Shrivastava said that the farmer unions, having promised that Tuesday's tractor rallies would stick to agreed routes, had "backstabbed" the authorities.

Twitter has also suspended several hundred accounts, most of them outside India, which were sharing "fake and inflammatory" reports to incite religious or regional violence around the protest, Shrivastava said.

Farming has long been a political minefield, with nearly 70 percent of the 1.3-billion-strong population drawing their livelihood from agriculture.

But the government says it is massively inefficient and in need of reform.

bb/stu/reb