More than 2,000 rural migrant workers blocked from returning home pelted Indian police with stones, officials in Gujarat said, as millions more stranded in the state readied to return to villages.
Poor migrant workers across the country lost their jobs during the world's biggest pandemic lockdown, which began in late March to guard against the spread of new coronavirus.
Saturday's clash in western India's Gujarat is the latest in a spate of such protests across India.
It happened when officials stopped the workers, who had rented vehicles, from crossing into neighbouring Madhaya Pradesh, Rajasthan and Uttar Pradesh states, because they did not have sufficient paperwork for entry, officials told AFP.
Gujarat is one of India's main industrial hubs, and authorities there were bracing for a logistical "nightmare" after about two million migrant labourers and their families signed up for permission to return home, an official in the state said.
They are clamouring to get back to their villages despite the fact that some might have the opportunity to work again. The government is pushing for factories to reopen and has eased some restrictions in the lockdown which will extend for two more weeks from Monday.
"Making arrangements for even half of the registered people would be a nightmare for the district administrations," the official, who asked to remain anonymous, told AFP.
In Indore, in the central state of Madhya Pradesh, 14 migrant workers and four others were found by police on Saturday crammed into a cement mixer, local media reported. The migrants had been trying to return home from western Maharashtra state to northern Uttar Pradesh state -- a 1,200-kilometre (745-mile) journey.
In a vast exodus, many migrant already managed to return to their villages, mostly on foot, but local media reported that some died on their long journeys. Others have been stranded at crowded shelters in cities.
The government late last week allowed special cross-border trains and buses to operate to bring those who wanted to return to their villages in other states.
Inter-state public transport is still barred.