(CNN) -- India is looking to Pakistan for answers after online threats and text messages sparked mass panic among migrant workers and students who hail from the country's northeast.
Indian Home Minister Shri Sushil Kumar Shinde said in a statement issued Monday that "elements based in Pakistan" had used social media to circulate false pictures and stories.
Students and workers from the northeastern state of Assam said last week they received text messages threatening retribution for ethnic violence that has gripped their state in recent weeks.
The texts and rumors prompted thousands of people to flee cities across India, including Mumbai, Pune, Hyderabad and Bangalore, the country's technology and outsourcing hub.
Pictures showed crowded station platforms and packed railway carriages although the situation is now calmer.
The Indian government also said on Monday that it had blocked a total of 245 web pages for hosting provocative content.
It said that images and video had been doctored, inciting comments from bloggers and users of social media and the sending of "hate SMSes."
"The initial response from international social networking sites indicates that such content has been hosted from outside the country and to a large extent from a neighboring country (Pakistan)," according to a statement from India's Information and Technology Ministry.
Mass text messages to more than five people have also been banned.
Shinde said he had expressed his concern about the misuse of social networking sites in a phone call to Rehman Malik, Pakistan's interior minister.
He asked for Pakistan's cooperation in investigating the claims.
However, according to media reports, Malik said he would investigate only if India provided evidence to back up its assertion that the content originated in Pakistan.
India's northeast is home to more than 200 ethnic and tribal groups.
Violence erupted in Assam in July after two Muslim boys were shot by members of the Bodos tribe, local police said.
Muslims retaliated by killing four Bodos. That triggered widespread rioting and since then at least 80 people have died and more than 300,000 have been displaced.
The Bodos, who are mainly Hindu, migrated to India decades ago but they fear being marginalized by the increasing number of Muslims, who cross the border illegally from Bangladesh.