Indian Premier Manmohan Singh warned Saturday over the use of social media to inflame ethnic tensions after online threats and text messages sparked a mass exodus of migrants from southern cities.
The use of "social media to aggravate the communal situation is a new challenge", Singh told a conference of senior police officials in New Delhi.
"We need to fully understand how these new media are used by miscreants... and devise strategies to counter the propaganda that is carried out by these new means," he said.
Tens of thousands of migrant workers and students from India's northeast fled last month from the high-tech centre of Bangalore and other southern cities.
The unprecedented exodus was triggered by inflammatory text messages and videos posted online which warned that Muslims would target them in reprisal for deadly clashes between the tribals and Muslims in remote Assam state.
The government imposed a two-week ban on bulk messages that ended in late August and blocked some Internet pages to halt the spread of incendiary material that could fuel tensions.
Ethnic clashes in India's northeastern state of Assam between the Bodo tribals and Muslims have claimed around 90 lives and prompted some 400,000 people to take refuge in camps.
India is a hugely diverse nation which prizes a reputation for secular tolerance but where ethnic and religious tensions often simmer beneath the surface.
The use of the text messages and videos posted online to stir up fears have been deeply alarming to Indian authorities.
Singh also spoke of "increasing infiltration attempts" by Pakistan-based militants into Indian Kashmir and across India's international border with Pakistan as the South Asian rivals held peace talks in Islamabad.
The warning came as Indian Foreign Minister S.M. Krishna was on a three-day visit to Pakistan, where he was to hold talks with his Pakistani counterpart Hina Rabbani Khar.
Last year, the nuclear-armed rivals resumed a tentative peace process that had collapsed after Islamist gunmen from Pakistan entered the coastal city of Mumbai by sea and killed 166 people in 2008.
While violence in Indian Kashmir has declined, militants are "maintaining their ability to use the sea route" to launch an attack against India, Singh warned.
India and Pakistan have fought three wars since independence in 1947, two of them over Kashmir. Each of them hold part of the Himalayan region but claim it in full.