Constable Priti Rani was among the hundreds of police personnel deployed for Adityanath's visit.
The letter by Singh, who is camping at the Dalit Prerna Sthal in Noida along with his faction members since December 2, came as protestors marked the birth anniversary of former prime minister and farmers' leader Chaudhary Charan Singh.
Police said the border has not been sealed but they are checking all vehicles entering the national capital.
The skyscraper, to be built as part of the ambitious Noida City Centre in Uttar Pradesh, will be higher than the 508 metre-high Taipei 101 in the Taiwanese capital, currently the tallest building in the world.
Babu, who teaches English at the Delhi University, was booked under Indian Penal Code sections 120B (criminal conspiracy), 121 and 121A (waging or attempting to wage war against government), 124A (sedition), among others.
Experts say the 12-hour long anti-terror operation is incontrovertible evidence of the fact that Islamic State has developed its roots in the country.
A 26-year-old unemployed man, who had been on the run after he allegedly raped and murdered his estranged fashion designer girlfriend in Uttar Pradesh's Noida city, has been arrested from Panvel, the police said on Tuesday.
The sky turned cloudy around 4:30pm and gusty winds swept the national capital.
Metro likely to keep lakhs of cars off city's roads