The Ghaziabad Development Authority (GDA) on Friday sealed a construction site in the Hindon river’s flood zone area behind Siddharth Vihar.Officials said several private persons were responsible for the construction activities, and the authority acted on a complaint about the same.Authority officials said structures for a stilt and four storeys were being constructed when a team of officers reached the site, along with a police team on Friday. According to official estimates, the construction was going on over a 20,000-square yard plot.“The entire construction was sealed. We also found that pits were dug up in adjoining flood zone areas as well and were meant for constructing other residential buildings. The building we sealed had four building blocks and was meant for the construction of flats. We have also written to the Vijay Nagar police to keep a tab over the premises that we finally sealed. The police have also been told to lodge an FIR if the seal is broken in any case,” VK Singh, officer on special duty (GDA), said.According to officials, the area was initially in name of a society and later sold to two private persons.“We have issued a show cause notice to the society as well as the two persons. The two told us they have sold the land to five other private persons. We have issued show cause notice to them as well. The entire construction will be demolished as no map layouts can be passed in the flood zone area and no permanent construction can be allowed,” Singh added.Officials said it was a new construction that was being carried out by private persons after sealing the construction area with safety nets.Apart from the new constructions, there are numerous constructions that are already in place over the flood zone of the Hindon river at Chijarsi, Kanawani and Vijay Nagar, etc.