By Chris Morris

BBC News, Delhi



Tribal people say they are being robbed of their rights Pic: Simon Williams

The march begins on a national holiday marking the birthday of Mahatma Gandhi, the man who introduced the idea of non-violent protest to the nation.

It is intended to raise awareness about land rights and due to last for nearly four weeks.

The organisers hope 25,000 people will take part in the march.

Thousands of people began gathering in the city of Gwalior in Madhya Pradesh, chanting and singing. Most of them are low caste and landless labourers or tribal people demanding legal rights over their land.

They are calling for a national authority to oversee land reform and a system of fast track courts to deal with the long delays in resolving land disputes.

Land reform is a huge issue in rural India. The system is often corrupt and unjust.

So over the next few weeks these protestors will walk more than 300km (180 miles) to Delhi, where their leaders hope to meet, among others, Prime Minister Manmohan Singh.

It is a huge logistical exercise.

Those taking part are being broken down into groups of one thousand, to make sure everyone gets fed.

The march has been dubbed Janadesh - People's Verdict - and it is described as non-violent civil disobedience.