NEW DELHI (Agencies) Indian government made an official protest to Washington Saturday over the security frisking of its envoy at a US airport and hinted it could lead to tit-for-tat action. Donald Lu, deputy chief of the US Embassy in New Delhi, was summoned to the Indian Foreign Ministry, the Press Trust of India (PTI) quoted officials as saying. Lu was told the airport check was contrary to the normal diplomatic practice and inconsistent with the excellent relations that India and the US enjoy, the national news agency quoted an unnamed official as saying. Last week, Indias envoy to the US, Meera Shankar, was pulled out of the security line at a Mississippi airport and subjected to a rigorous pat-down, according to Indian officials. Protocol normally exempts envoys and other dignitaries from such searches. PTI said Indias protest was conveyed by senior ministry official Javed Ashraf. She had pointed (out) her diplomatic identity but had to undergo the security checks because, as we have been informed, she was wearing a sari, PTI quoted Ashraf as telling the US diplomat. We understand and respect every countrys security procedure but we also expect normal diplomatic privileges and courtesies are extended to the ambassador and diplomats, he said. Such incidents naturally lead to calls for a review of privileges and facilities given in India (to foreign diplomats), Ashraf added, without elaborating. In September, Shankar suffered a similar experience at a Chicago airport. Mumbai-based DNA newspaper quoted US Secretary of State Hillary Clinton as expressing concern over the latest incident. We will be looking into it and trying to determine both what happened and what we could do to prevent such incidents in the future, Hillary said. Officials at the US embassy were not immediately available for comment. Meanwhile, the US on Saturday tendered an official apology to India and Indian envoy Meera Shankar over her pat down by an American security agent at the Jackson-Evers International Airport.