Karachi, Jan 6: An image from Google Earth has revealed the presence of  Chinese nuclear submarine docked at the Karachi harbour, is likely being used to scrutinise the movements of Indian warships. Indian nuclear experts say that the submarine could be the powerful Chinese Type-093 Shang class,  which is very tough to detect. Unlike conventional submarines, nuclear-powered submarines have an unlimited range of operations.  Such submarines are armed with torpedoes and cruise missiles, can be deployed underwater for extended durations where they are difficult to track.  Nuclear submarines are also faster than their conventional counterparts.Also Read - Legendary Pakistani Journalist Chand Nawab Puts His Viral 'Karachi Se' Railway Video Up for Auction with Minimum Bid Price of Rs 46 Lakhs

The image was posted on Twitter by a satellite imagery expert (@rajfortyseven); it shows two Chinese PLA Navy submarines docking at Karachi. The submarines are the Type 091 Han-class nuclear-powered submarine and the Type 039 Shang-class diesel-electric submarine. Also Read - Pakistan: 13 People Dead, Several Others Injured in Grenade Blast in Karachi

This is not the first time Chinese submarines have been spotted in the Indian Ocean region. Earlier in 2014, Chinese submarines had docked at Colombo and at Karachi in May 2015. Also Read - Pakistan: Cash Van Driver Flees With 200 Million Rupees In Karachi

India has been saying that it is aware of the presence of Chinese nuclear submarines in the Indian Ocean. Recently Navy Chief Sunil Lamba said that the Indian Navy keeps a close watch and monitors movements of the Chinese submarines and ships.