Chinese fishermen who were detained by the Sri Lanka navy are still on their trawlers and are safe, the Chinese embassy in Sri Lanka said on Monday.

The embassy said the Chinese fishermen work on Sri Lankan vessels and that authorities are working to determine if they were detained on suspicion of illegal fishing. It said it is speaking with Sri Lanka about an investigation into the case.

Commander Kosala Warnakulasuriya, Sri Lankan navy spokesman, was quoted by Xinhua News Agency on Monday as saying the Chinese were arrested for fishing illegally in Sri Lankan waters and will be handed over to police for a further investigation.

The fishermen were aboard two fishing trawlers when they were spotted off the eastern coast of Batticaloa, he said, adding that two Sri Lankans were also arrested in the case.

The Sri Lankan navy said it detained 37 Chinese fishermen on Sunday night.

The Chinese embassy said it has urged Sri Lankan authorities to deal with the matter in accordance with the law, ascertain the facts in the case and release the Chinese fishermen as soon as possible.

Marine fisheries are of considerable social and economic importance around Sri Lanka’s 1,770km coastline.

According to the website illegal-fishing.info, fish are the source of 60 percent of the animal protein eaten by Sri Lankans, of 2 percent of the country’s GDP and of the livelihoods of about 1 million people there.

In recent years, the fisheries industry in Sri Lanka has emerged as an important source of foreign exchange through exports of several types of valuable fish and fishery products, including chilled and frozen tuna, as well as other marine products such as shrimp, lobster, shark fins and sea cucumber.