BJP leader and Bihar's animal and fisheries minister Giriraj Singh, said a case of sedition should be filed against Thackeray.
"If Raj Thackeray has given such a statement, then he must have lost his mental balance. Nobody can be permitted to spread discord", he said, asking the Election Commission to disqualify parties that are trying to divide the nation.
"He (Raj Thackeray) has a habit of saying such things. He keeps making such baseless allegations. This problem is not related to one state," said Janata Dal (United) leader Ali Anwar Ansari.
Thackeray at a rally in Mumbai on Saturday night said: "All are talking about the Delhi gangrape, but nobody is asking from where these accused came from. So many cases are slapped against me (for speaking against Biharis) but no one is talking about the fact that all these rapists are from Bihar".
Thackeray said that even New Delhi chief minister Sheila Dikshit has blamed migrants for increasing crime in her state.
"She (Dikshit) told this to her party president Sonia Gandhi and Prime Minister Manmohan Singh," he said.
Maharashtra Congress spokesperson Sachin Sawant said that Thackeray's was a highly irresponsible statement.
He said that several MNS workers from Maharashtra were arrested for serious crimes like rape and criminal assault.