The recent exposure of human smuggling involving MPs and others has apparently prompted stepped-up vigilance by the US embassy, which today 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 co-operating with the 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 the emigration racket.US Consul General Peter G Kaestner insisted that the steps planned by the embassy were "not related" to the alleged involvement of some MPs in the human trafficking case.The alleged involvement of MPs in the human trafficking scandal came to light after the arrest of BJP MP Babubhai Katara about two months ago. Investigations have indicated the involvement of some other MPs in the racket.Embassy officials said the US encourages "legitimate Indian travellers" but some visa consultants and individuals have been found "misleading" the people by telling them that the US has simplified visa rules and "now is the time to get easy visas" in a clear case of "consumer fraud"."We have not changed our visa regulations or laws or procedures in terms of qualifying for a visa. Indians still must qualify just like they did before out visa efforts to increase the availability of appointments," Kaestner said.