Here are the 10 big developments on this story:
The VHP said it inaugurated its tour -the chaurasi kosi yatra- in Ayodhya this morning with a group of 40-odd members. But the organization's international president Ashok Singhal was detained as soon as he landed at the Lucknow airport. He has refused to leave the airport.
This was just after another senior leader Praveen Togadia was arrested in Ayodhya, where he attempted to conduct prayers on the banks of the Saryu river to launch the tour. Mr Togadia was later sent to custody for 14 days. Over 600 people, including former MPs and other leaders, have now been arrested as a preventive measure, many of them in different UP towns as they set out to join the yatra.
Soon after his arrest, Mr Togadia said demonstrations would be staged all over the country tomorrow against the ban by the UP government on the yatra.
The state government says it has banned the tour to prevent an eruption of communal tension. Chief Minister Akhilesh Yadav and his father, Samajwadi party chief Mulayam Singh Yadav, have ordered the police and administration to stop VHP leaders from reaching Ayodhya.
The VHP accuses them of using the ban to ingratiate themselves with the state's large Muslim population, which is a large part of their support base.
The BJP has kept away from the thick of the yatra controversy so far, though it has supported the VHP's "fundamental right to hold a yatra" and has slammed the Uttar Pradesh government for being "over-prepared" for a procession that, it claims, is to be performed by "just 250 saints". But the VHP said 5,000 seers and saints from across the country would join the yatra, which it claimed was a legitimate annual tradition.
VHP activists have promised a high-decibel campaign to demand the construction of a Ram mandir or temple for Lord Ram at the disputed site where the 16th-century Babri Mosque was destroyed in 1992, triggering massive communal riots.
The VHP is affiliated to the Rashtriya Swayamsevak Sangh or RSS, which is the ideological mentor for the BJP, the main opposition party. The Ram Mandir issue has been listed as an important constituent of the party's campaign for the national election, due by May.
Not all religious heads are supporting the yatra. Acharya Satyendra Das, Ayodhya's top priest who takes care of a makeshift Ram temple in the city said the yatra is "political, not religious" and says many others like him do not support it either. The priest says this is not the stipulated time for a 84 kos parikrama which is usually held in April-May. The parikrama, a 300-km walk encircling Ayodhya, has not been held in the last 50 years.
The tour's intended route sees the VHP passing through six districts where Muslims are in the majority.
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