Expelled RJD parliamentarian Pappu Yadav on Wednesday threatened to pull out Manipuri passengers from trains running through Bihar and send them back to Manipur in protest against the violence against Bihari migrants in the northeastern state."If the situation did not improve or violence against Bihari migrants continue in Manipur, forcibly pull out Manipuri passengers from trains running through Bihar and send them back to Manipur," Yadav, the chief of the Jan Adhikar Party, said here.He said Prime Minister Narendra Modi should intervene over the violence against Bihari migrants in Manipur.Yadav said Modi and Chief Minister Nitish Kumar were both responsible for what was happening in Manipur."Modi and Nitish Kumar should talk to the Manipur government immediately to stop the violence," he said, seeking protection for Biharis in Manipur.