NEW DELHI: India has demanded social networking websites take down provocative messages and has blocked some online content after anonymous threats sparked an exodus of migrants from several cities.

Tens of thousands of workers and students from the remote northeast region returned home last week fearing attacks from Muslims in reprisal for recent ethnic clashes in the state of Assam.

The Indian government has said many of the internet posts, fake video clips and phone messages spreading rumours of plans to target migrants were sent from arch-rival Pakistan.

A statement from the Ministry of Communications late Monday said an order had been issued on August 17 but that “such inflammatory and harmful content continued to appear on the social networking sites.”

It added the government was meeting with representatives of the sites to curb the content, but stressed that “a lot more and quicker action is expected from them to address such a sensitive issue”.

Officials declined to name which sites were affected, and Twitter, Google and Facebook were not immediately available for comment.

The government also said 245 web pages had been blocked, but declined to give further details.

Asked on Tuesday whether the sites were being used to whip up ethnic tension, Home Minister Sushil Kumar Shinde told reporters: “We have got sufficient evidence. The whole process is in investigation mode.”

Local media reports estimated that over 35,000 people fled cities including Bangalore and Mumbai over the last week, packing special trains arranged to carry panicked students and workers back to the northeast.

Weeks of clashes in Assam between members of the Bodo tribal community and Muslims have claimed at least 80 lives and displaced more than 400,000 people.

The government says it is willing to share proof that much of the inflammatory Internet activity originated from Muslim-majority Pakistan.

Bulk text messages have been temporarily banned in India to halt the spread of threats and rumours.