India has deployed more than 5,000 troops and police in the northern town of Ayodhya in advance of an expected Supreme Court ruling on Saturday over control of a religious site disputed by Hindus and Muslims.
Hundreds of people were detained on Friday amid fears of violence.
Muslims said they prayed at the medieval era Babri Mosque for centuries until idol of Ram deity was surreptitiously placed inside the mosque in 1949.
Hindus believe that the mosque was built under Mughal ruler Babur after destroying a Hindu temple. They believe that the site of the mosque is the birthplace of one of their most revered deities, Lord Ram.
In 1992, Hindu mobs demolished the Babri mosque, and constructed a makeshift temple of Lord Ram, a physical incarnation of the god Vishnu, who is believed to have been born at the site.
The decision is due on Saturday at about 10:30 local time (05:00 GMT).
Schools and colleges in the area have been closed and all roads leading to the site have been blocked by police.
Social media platforms were being monitored for inflammatory posts ahead of the verdict, told by provincial police chief Om Prakash Singh.
“We will not tolerate Hindus or Muslims publicly displaying their reaction to the court verdict,” he said.
Government departments say they have also made preparations to deal with any violence.
Prime Minister Narendra Modi, whose Hindu nationalist Bharatiya Janata Party has campaigned on promises to build a Hindu temple in place of a medieval-era mosque, called for calm.
“Whatever decision the Supreme Court arrives at on Ayodhya, it will not be a victory or defeat of anyone,” Modi tweeted on Friday.
Muslim religious leaders have called for peace and appealed Muslims to respect court judgment in Friday sermons in many parts of the country.
Navaid Hamid, president of the All India Muslim Majlis-e-Mushawarat, the top forum for Islamic organisations, said thousands of Muslim religious leaders had pledged to maintain peace and harmony after the court verdict.
“The land can belong to Hindus or Muslims, but there will be no repeat of the 1992 communal violence,” said Hamid.
Ayodhya – considered one of the holiest Hindu sites – is visited by religious pilgrims from all over India throughout the year.
The Supreme Court has to decide on the appeals against a key 2010 verdict by the High Court which ruled that both groups should split the site, with Hindus granted the lion’s share.
The court had ruled that the disputed area of 2.77 acres (1.12 hectares) be divided into three equal parts, with two-thirds going to the Hindu community and one-third to Muslims.