Thousands of right wing Hindu activists have begun a march to the Indian capital Delhi to press for the construction of a temple at a disputed site in the northern town of Ayodhya.
The demolition of the mosque nine years ago sparked communal riots in which about 2,000 people died.
Nearly 5,000 people have joined the rally which began from Ayodhya.
Travelling in cars and buses, they are expected to reach Delhi by 27 January.
The demonstration has been organised by right wing Vishwa Hindu Parishad party (VHP).
Radical Hindus are demanding that a temple to the god Ram be built on the ruins of a mosque in Ayodhya, which they say marks his birthplace.
Internal differences
The rally started from Ayodhya amid tight security arrangements.
Anti-riot police are accompanying the protesters who are expected to pass through Lucknow, the capital of Uttar Pradesh.
But the Chairman of VHP's Temple Committee, Ram Chandra Paramhansa, has boycotted the rally.
He said the state administration had imposed unnecessary restrictions in the town which he said affected normal life.
Mr Paramhansa said he would work for the defeat of the state's governing Bharatiya Janata Party in the forthcoming assembly elections.
Senior VHP leaders are now trying to pacify him.
Fresh initiative
The demonstration comes at a time when the Prime Minister, Atal Behari Vajpayee, has launched new efforts to resolve the controversy over the disputed site.
Mr Vajpayee has set up an Ayodhya committee in his office and appointed a senior official to hold talks with Hindu and Muslim leaders.
He had also appealed to the VHP to cancel its march to Delhi but this was ignored.
The state of Uttar Pradesh, the largest in India, is currently ruled by Mr Vajpayee's Bharatiya Janata Party.
Elections to the state legislatures scheduled for next month are expected to be dominated by the row surrounding the Ayodhya mosque.