Acclaimed Pakistani singer Ustad Rahat Fateh Ali Khan was in for a rude shock on Thursday morning when he touched down at the city's Rajiv Gandhi International Airport (RGIA). For, within moments of landing in Hyderabad on an Emirates flight, he was barred entry and asked to return to Abu Dhabi. The Ustad had travelled to the city to perform at a New Year eve event at the iconic Taj Falaknuma Palace.Immigration authorities at RGIA attributed Rahat's deportation to "technical flaws". According to immigration rules, Pakistani nationals can't enter India through Hyderabad; the legal ports of entry by air are Delhi, Mumbai, Kolkata and Chennai."That's why the singer was asked to return to Abu Dhabi and travel to the city through the valid entry points," the official said. He added, "If a Pakistani national enters through any other airport, except the four metros, his/her travel to India cannot be recorded. So it is mandatory that they stick to the four ports. This system has been put in place to monitor the movement of Pakistani nationals in and out of the country."But, immigration officials refrained from confirming the same. They said they noticed a violation of rule in the travel papers that led to his deportation. "There was a technical issue with his documentation and he was deported to Abu Dhabi on the same flight," an immigration official told TOI.Due to his unexpected deportation, the performance of the Ustad scheduled for 8 pm was rescheduled for 11 pm. When contacted, a member of the event organizing team, Apurva, confirmed the same to TOI.Incidentally, the Sufi music event at the Falaknuma Palace was designed to promote harmony through Hyderabad's heritage and culture.Inquiries by TOI revealed that soon after news of the singer's deportation spread, the event organizers managed to get a clearance from the concerned departments of the Union government, including the ministry of home affairs and made it possible for the Ustad to return to Hyderabad.According to sources, Rahat Fateh Ali took a flight to Delhi from Abu Dhabi on Thursday evening then boarded a chartered flight to RGI Airport from the national capital.