By Arjuna Ranawana and Nidhi Verma
COLOMBO/NEW DELHI (Reuters) - A new fire broke out on a supertanker carrying about 2 million barrels of oil in the Indian Ocean off the east coast of Sri Lanka, spokesmen for the country's navy said on Thursday, adding that one of its 23 crew was missing and another injured.
Navy spokesman Captain Indika de Silva said flames had spread to the New Diamond's bridge, but there was no damage to the cargo area.
"We will need an international effort," de Silva said.
He said earlier navy personnel at the scene had reported the fire was under control.
A statement released late on Thursday by the navy said the New Diamond, a very large crude carrier (VLCC), was crewed by 5 Greek and 18 Philippine nationals.
One Philippine national was injured and another was missing following the fire, the statement said. Two Russian anti-submarine ships and four Indian ships were assisting in the operation.
Authorities "are taking steps to mitigate and manage the risk of possible oil spills in future due to this disaster," the statement said.
The New Diamond, chartered by Indian Oil Corp (IOC), was fully loaded with about 2 million barrels of oil, Refinitiv data showed.
Photographs taken by Sri Lanka's air force showed extensive damage to the tanker's funnel, and thick black smoke and flames coming from the bridge, which is just behind the cargo area.
Another spokesman, Commander Ranjith Rajapaksa, said the VLCC was ablaze about 20 nautical miles off the east coast of Sri Lanka and that the military had sent an aircraft and two ships to assist.
On Twitter, India's coast guard said it had sent several ships and aircraft to help fight the fire.
New Diamond sailed from the port of Mina Al Ahmadi in Kuwait, loaded with Kuwait Export Crude, Refinitiv Eikon tracking data showed. It was heading for the Indian port of Paradip, where state-run IOC has a 300,000 barrel-per-day refinery.
GRAPHIC: Path of the VLCC New Diamond, which caught fire off Sri Lanka - https://fingfx.thomsonreuters.com/gfx/ce/rlgpdoqjgvo/NewDiamond.png
Sri Lanka's Marine Protection Authority said it would take measures to prevent any possible oil leak from the tanker.
Such a spill could cause an "environmental disaster," Ashok Sharma, managing director of shipbroker BRS Baxi in Singapore, said.
"No double-hull VLCC has spilt oil to date, but (it) depends on the damage to the ship," he added.
Thursday's incident happened just over a month after a state of "environmental emergency" was triggered by the spill of about 1,000 tonnes of fuel oil from a Japanese bulk carrier, MV Wakashio, when it ran aground on a reef in Mauritius.
De Silva said some of the New Diamond's crew were rescued by oil product tanker Helen M, which an industry source said was on a time charter with India's Reliance Industries.
"The fire happened at 7.45 a.m. India time," said the source, who spoke on condition of anonymity. "The nature is explosion and fire and serious injury to the crew."
In a statement, the vessel's insurer, West of England, said: "We can confirm that these two vessels are entered in the West of England. The Club is liaising closely with our members and the relevant authorities and it would be inappropriate to comment further at this time."
The second vessel referred to was the Gulf Livestock 1, sailing to China from New Zealand with 43 crew and nearly 6,000 cattle that sank off Japan on Thursday.
IOC, Reliance Industries and Kuwait Petroleum Corp had no immediate comment.
(Reporting by Nidhi Verma in New Delhi, Waruna Karunatilake and Arjuna Ranawana in Colombo, Roslan Khasawneh in Singapore and Jonathan Saul in London; Writing by Alasdair Pal; Editing by Jason Neely, Clarence Fernandez, Catherine Evans and Barbara Lewis)