BEIJING (AP) — Several ships and aircraft searched Wednesday for 39 people reported missing after a Chinese fishing boat capsized in the middle of the Indian Ocean.

Chinese state broadcaster CCTV said the accident happened around 3:00 am Tuesday. The report said the crew includes 17 from China, 17 from Indonesia and five from the Philippines.

Chinese leader Xi Jinping and Prime Minister Li Qiang have ordered Chinese diplomats abroad, as well as the agriculture and transportation ministries, to assist in the search for survivors.

“All-out efforts” must be made in the rescue operation, Xi was quoted as saying by the official Xinhua News Agency. Li ordered unspecified measures to “reduce casualties and strengthen safety management of fishing vessels at sea to ensure safe maritime transport and production,” Xinhua said.

No word was given on the cause of the capsizing.

Australia, Indonesia and the Philippines have also expressed their willingness to join in the search. Indonesia’s National Search and Rescue Agency said the capsizing occurred about 4,600 kilometres (2,900 miles) northwest of Australia.

Several ships and an Australian Defense Force P-8A Poseidon aircraft have been searching the area. The Indian Ocean stretches from South Asia and the Arabian Peninsula to east Africa and western Australia. No survivors or life rafts have been spotted.

The Philippine Coast Guard Command Center said Wednesday it was monitoring the situation and coordinating with the Chinese Embassy in Manila, as well as search and rescue teams operating near the vessel’s last known location.

The Australian Maritime Safety Authority said it was coordinating the search in what it called a remote location in the Indian Ocean, about 5,000 kilometres (3,100 miles) northwest of the coastal city of Perth. It said the agency received a distress beacon signal from the fishing vessel at about 5:30 am Tuesday, Australian time, and that weather conditions in the area Tuesday were “extreme,” but had improved by Wednesday.

Along the Bay of Bengal at the Indian Ocean’s northern end, Myanmar and Bangladesh were undergoing recovery from a powerful cyclone that smashed into their coastlines, causing widespread destruction and at least 21 deaths, with hundreds of others believed missing.

Merchant and fishing vessels in the area were also searching for survivors Wednesday.

A Perth-based Challenger rescue aircraft will drop a buoy to help with drift modelling to further assist in the search, the agency said.

The search covered an area virtually in the centre of the Indian Ocean. The capsized hull was spotted and the transmitter detected more than 1,000 kilometres (620 miles) south of Sri Lanka, with the nearest port appearing to be the island chain of the Maldives, about 500 kilometres (310 miles) to the north of the search area.

The Lu Peng Yuan Yu 028 was based in the eastern coastal province of Shandong, operated by the Penglai Jinglu Fishery Co Limited, according to the reports. Another Chinese vessel, Lu Peng Yuan Yu 018, is operating near to the upturned hull and has been asked to conduct a grid search for survivors, according to the Indonesian agency.

Chinese Foreign Ministry spokesperson Wang Wenbin said additional rescue assets were on their way to the scene.

“We will continue to take all measures possible with all parties to search and rescue the missing persons. The Chinese side thanks the Australian maritime search and rescue department for promptly dispatching aircraft and coordinating passing foreign ships to participate in the search and rescue,” Wang told reporters at a daily briefing Wednesday.

China is believed to operate the world’s largest fishing fleet. Many of them stay at sea for months or even years at a time, supported by Chinese state maritime security agencies and a sprawling network of support vessels.

Chinese squid fishing ships have been documented using wide nets to illegally catch already overfished tuna as part of a surge in unregulated activity in the Indian Ocean, according to a report released in 2021 by a Norway-based watchdog group that highlighted growing concerns about the lack of international cooperation to protect marine species on the high seas.

The group, called Trygg Mat Tracking, found that the number of squid vessels in the high seas of the Indian Ocean — where fishing of the species is not regulated — has increased six-fold since 2016.

The US Coast Guard was also involved in a dangerous confrontation with Chinese vessels not far from Ecuador’s Galapagos Islands in 2022 during a mission to inspect the vessels for any signs of illegal, unreported or unregulated fishing.

Chinese fishing vessels operating illegally are known to sail “dark,” with their mandatory tracking device that gives a ship’s position either switched off, transmitting intermittently, or providing false identifiers.

In 2014, Malaysia Airlines Flight 370 was believed to have gone down somewhere in the Indian Ocean with 239 people aboard. That Boeing 777, which remains missing, became invisible to civilian radar when its transponder locating device stopped transmitting during a flight from Kuala Lumpur.