New Delhi, Jan. 21 -- Prime Minister Narendra Modi on Tuesday sounded an alarm over "ghuspaithiyas" or illegal immigrants and "urban naxals" and said the government will act against these groups that pose a threat to the country's security and political parties that "offer them security" should be exposed. Both have featured prominently in the party's electoral campaigns, making the PM's mention of them significant ahead of five state elections early this summer. "Today, a very significant challenge before the country is that of infiltrators. Even powerful countries in the world are acting against infiltrators in their own nations and expelling them," he said while addressing the party workers after the election of the BJP's new national president Nitin Nabin. In an indication of the government's tough stance against these groups, the PM said no nation accepts infiltrators. ".India too cannot allow infiltrators to rob its poor and youth of their rights. Infiltrators pose a very serious threat to the country's security," he said....