India’s security concerns have been reignited by the arrival of a Chinese navy vessel at a port in southern Sri Lanka that Beijing rents from the government.

Senior Sri Lankan and Chinese officials greeted the Yuan Wang 5 on Tuesday morning when it arrived at the Beijing-built Hambantota port with a customary ceremony, complete with a red carpet and a giant banner reading: “Hello Sri Lanka, Long Live Sri Lanka-China Friendship.”

The arrival of the ship, even if just for a few days, has set off alarm bells in India, which has long viewed China’s growing power in the Indian Ocean with skepticism. Since the United States and its western allies have long criticized Beijing’s dealings with Sri Lanka, analysts say they will also be keeping a careful eye on Yuan Wang’s actions.

The Yuan Wang 5 is a “scientific research ship,” as officially described by Sri Lanka. According to Prof Srikanth Kondapalli, dean of the faculty of international studies at Jawaharlal Nehru University, “the concern here in India is that despite Chinese critics’ claim it is civilian, it may have military functions.”

The latest development was discussed in Indian media on Tuesday. According to the Indian Express, “the Yuan Wang 5 is a strong tracking craft whose enormous aerial reach – apparently approximately 750km” means that China may be keeping tabs on ports in Kerala, Tamil Nadu, and Andhra Pradesh.

When a small, bankrupt nation like Sri Lanka hosts a Chinese surveillance ship at its commercial port of Hambantota, it is a stunning reminder of both India’s feckless foreign policy and receding influence in its strategic backyard, as a former member of India’s national security advisory board, Brahma Chellaney put it on Twitter.

Wang Wenbin, a spokesman for China’s Ministry of Foreign Affairs, brushed off these worries.

At a press conference on Tuesday, he said, “The marine scientific study done by the research ship Yuan Wang 5 adheres to international law and international common practice and will not damage the security and economic interests of any country.”

In the past few months, Sri Lanka’s economy has been in a tailspin. About 10% of the total foreign debt is made up of loans from China. However, India has also just loaned around $3.8bn to Sri Lanka to assist them to weather the economic storm.

The significance of China’s move on the international stage Colombo, stuck between two major countries in an economic downturn, has a diplomatic balancing act that Sri Lanka demonstrates. It also happened right after New Delhi gave Colombo a plane for spying on the ocean on Monday. Delhi claimed the move was made to better combat issues like human and drug trafficking as well as other crimes committed in its coastal waterways.

Last week, Arindam Bagchi, a spokesperson for the Indian Ministry of Foreign Affairs, stated that India was aware of the vessel’s scheduled visit and that it would take all necessary precautions to preserve its security and commercial interests.

Also, Delhi “rejected insinuations” that it had urged Sri Lanka to hold up the Chinese ship. Before giving the final approval to the Chinese vessel, Colombo claimed to have “engaged in lengthy deliberations at a high level through diplomatic channels with all parties concerned.”