NEW DELHI (AFP) - The son of an Indian minister has been arrested on preliminary charges of murder, police said on Sunday (Oct 10), a week after the death of eight people during a farmers' protest sparked national outrage.

Mr Ashish Mishra was detained in Uttar Pradesh late last Saturday over the incident in the northern state's Lakhimpur Kheri district, where farmers were demonstrating as part of their year-long campaign against contentious agriculture laws.

Farmers claimed that a convoy belonging to Mr Mishra and his father - junior home affairs minister Ajay Mishra - slammed into protesters, killing four of them.

Angry demonstrators then set fire to several cars and four other people, including a driver and a journalist, who were killed, according to the authorities and local media reports.

Mr Ashish Mishra was arrested on grounds of "non-cooperation" and "evasive replies" during an hours-long interrogation, Deputy Inspector General of Police Upendra Kumar Agrawal told reporters.

He will face court on Monday and formal charges have to be filed within 90 days.

Mr Mishra and his father have denied the allegations.

India's Supreme Court said last Friday that it was "not satisfied" with the police investigation of the case and questioned why the younger Mr Mishra had not yet been arrested.

The incident was the deadliest since farmers started camping on the outskirts of the capital, New Delhi, in November last year demanding a repeal of the controversial laws.

The agriculture sector, which employs some two-thirds of India's 1.3 billion population, has long been a political minefield.

Prime Minister Narendra Modi's government says the sector is massively inefficient and in need of reform.

But farmers fear the changes will leave them at the mercy of big corporations.