New Delhi: Chinese ‘research ship’ Shi Yan 6 arrived in Sri Lanka on Wednesday, South China Morning Post reported. In September, the Sri Lankan Ministry of Defence had given the ship permission to dock at Colombo.As The Wire has reported, Chinese “research ships” are said to usually have dual purposes. While the primary aim is scientific exploration, what raises the hackles of other countries is the geopolitical purposes for which they are also deployed.“Clearance was given for the vessel to come to Colombo for replenishment,” a Chinese foreign ministry spokesman told South China Morning Post.Both Indian and US officials had reportedly expressed concerns to their counterparts in Colombo over the docking.According to China, Shiyan 6 (Experiment 6) is out on an “expeditionary voyage” in the eastern part of the Indian Ocean, after it had left Guangzhou, south China’s Guangdong Province. “Organised by the South China Sea Institute of Oceanology (SCSIO) under the Chinese Academy of Sciences, the vessel is scheduled to operate at sea for 80 days with 28 scientific research projects from 13 research teams onboard, covering a range of more than 12,000 nautical miles (roughly 22,200 km),” a report from China’s state-run news channel CGTN had said earlier this month.The concern over the visit of the Chinese vessel is due to the fact that it comes months after a Chinese warship was docked at the Colombo port for a few days. Earlier, another Chinese military ship, Yuan Wang 5, had visited Sri Lanka’s Hambantota port in August last year even after India as well as the US had expressed their concerns. China, at that time, had said that it “completely unjustified for certain countries to cite the so-called ‘security concerns’ to pressure Sri Lanka”.Despite Sri Lanka’s reassurances, India has conveyed to Colombo that it has misgivings about the visit of Chinese vessels to ports in Sri Lanka. However, Sri Lanka has been trying to underline to India that it will not allow its territory to be used for any activity that would threaten the security interests of India in the region.