A Muslim man has died after he was attacked by hundreds of Hindu vigilantes while transporting cows in India, police said Wednesday, amid rising tensions over the slaughter of the sacred animal.

Pehlu Khan, 55, died in hospital late Monday, two days after a mob attacked his cattle truck on a highway in Alwar in the western state of Rajasthan.

Cows are considered sacred in Hindu-majority India, and their slaughter is illegal in many states.

In parts of northern and western India, squads of vigilantes roam highways inspecting livestock trucks for any trace of the animal.

Alwar police chief Rahul Prakash said at least six others were injured in the attack, but had now been discharged from the hospital.

Police are still trying to identify the attackers and have filed a murder case, he said, adding that a postmortem would determine the cause of Khan's death.

“We are yet to receive the postmortem report but he had multiple rib fractures,” he told AFP.

Prakash said the victim and his associates were returning to their home state of Haryana when the mob intercepted their vehicle.

At least 10 Muslim men have been killed in similar incidents across the country by Hindu mobs on suspicion of eating beef or smuggling cows in the last two years.

In 2015 a Muslim man was lynched by his neighbours over rumours that he had slaughtered a cow. Police later said the meat was mutton.

Critics say the vigilantes were emboldened by the election in 2014 of Prime Minister Narendra Modi's Hindu nationalist Bharatiya Janata Party.

Last year Modi criticised the cow-protection vigilantes and urged a crackdown against groups using religion as a cover for committing crimes.

But last month, he appointed a right-wing Hindu priest to head the country's most populous state Uttar Pradesh, which is also home to much of the country's meat industry.

Shortly after he was sworn in, police began shutting butcher shops, grinding much of the industry to a halt.