Recent exposure of human smuggling racket involving some MPs and others has apparently prompted stepped up vigilance by the US Embassy, which on Wednesday warned that those using fraudulent documents for visas would face legal action.

Embassy officials said they were alarmed by the mad rush of clearly unqualified visa applicants in recent weeks and is cooperating with Indian government agencies to arrest people who turn up with false documents.

"There are individuals and companies who are taking advantage of Indian citizens by suggesting they can provide a short cut to an American visa... We want to make it clear that no firm or person can help you obtain a US visa," Geoff Pyatt, Charge d'Affaires at the US mission, said.

"In the light of this rush and in the wake of reports about human smuggling to the US and other countries, the US mission is increasing its vigilance to eliminate illegal smuggling and visa fraud," Pyatt said without citing any specific instance about emigration racket.

Peter G Kaestner, Consul General at the Embassy, insisted that the steps planned by the Embassy were not related to the alleged involvement of some MPs in human trafficking case.

The alleged involvement of MPs in the human trafficking scandal came to light after arrest of BJP lawmaker Babubhai Katara about two months ago. Investigations have indicated involvement of some other MPs in the racket.