By Sunil Raman
BBC News, Delhi
The Indian government is sending security reinforcements to the states of Punjab and Haryana amid signs of growing religious violence.
The trouble has been brewing for days
Thousands of Sikhs, many armed, have been staging protests, some violent, against a religious sect.
They accuse the Dera Sacha Sauda (DSS) sect of insulting Sikhism.
Tensions began when the DSS leader appeared in an advert in which Sikhs said he was dressed as the last Sikh Guru, Gobind Singh.
Swords and bricks
Tens of thousands of Sikhs and DSS supporters have been gathering in various places in Punjab and Haryana.
Some Sikhs have been armed with swords and bricks. They are reported to be surrounding a DSS campus near Salabetpura in the Punjab.
Many DSS supporters have gathered in Sirsa in Haryana, where the sect has its headquarters, to ward off any attack by Sikhs.
The central government has sent two battalions of the Rapid Action Force, a paramilitary force comprising commandoes, to Sirsa.
Indian Interior Minister Shivraj Patil presided over a security meeting in Delhi on Thursday evening.
The Punjab and Haryana governments have been asked by the federal government to ensure that law and order is maintained.
Punjab's Chief Minister, Parkash Singh Badal, has asked the federal government to despatch 50 companies of paramilitary forces to ensure peace.