Hunters are on the prowl for an unusual prey on the streets of Iran's capital, Tehran. Authorities in the city have deployed snipers to tackle a growing rat infestation. Piling rubbish and open waterways have led to a boom in Tehran's rat population. In Islamic - Iranian culture it is advised that food is respectable as God's blessing and should not be mixed with other waste. Municipal authorities say there is two-million of the rodents plaguing the city. But residents fear the real figure is far higher, with estimates ranging from 20-70 million. Report by Ferdia Carr.