The famous 1930 "salt march" by India's independence hero Mahatma Gandhi to defy British colonial rule is being re-enacted for its 75th anniversary.
Cabinet ministers joined the start of the re-enactment march
The march of several hundred is led by Gandhi's great-grandson Tushar Gandhi.
Mahatma Gandhi undertook the 24-day walk from Ahmedabad to the coastal village of Dandi to manufacture salt.
It sparked India's civil disobedience movement as thousands joined him on the beach to pick up salt, the production of which was under government control.
The Italian-born president of India's governing Congress Party, Sonia Gandhi, launched the march in a ceremony at Sabarmati Ashram, once Mahatma Gandhi's commune in Ahmedabad, Gujarat.
The BBC's Sanjeev Srivastava said the ceremony was solemn, almost subdued, and was interspersed with the independence leader's favourite prayers.
Mrs Gandhi urged those carrying out the 380km (240 miles) to take forward Mahatma Gandhi's message of "peace and non-violence".
Mahatma Gandhi's aim at the end of the Dandi walk was to manufacture salt and defy the monopoly on salt production by the British colonial rulers.
The unique, non-violent protest forced the British to take note of the growing civil disobedience movement in the country.
Mahatma's great-grandson Tushar and several hundred fellow marchers will follow the same route and take a similar length of time to walk it.
But there the similarities with the 1930 march end, says our correspondent.
The values that Mahatma Gandhi lived and died for - such as non-violence, religious tolerance and honesty in public life - are as alien to today's India as the days of the Raj, says our correspondent.
Gandhi was known for his simple ways, but the sequel march was something of an extravaganza.
Saturday's march was attended by nearly half of the Indian cabinet, many of whom walked for a few kilometres before returning to their hotels, our correspondent observed.
Tushar Gandhi acknowledged there was little to compare his march to his great-grandfather's, although he said they carried the same message of religious harmony, brotherhood and peace.
"The comparison is that all the Dandi walkers who have come from all over the world are volunteers. They came... because they identified with this battle and I think that is the spirit," he told the BBC.