WELLINGTON - New Zealand maritime rescue authorities say the three crewmen killed in a fire on a Korean fishing boat near Antarctica Wednesday were Vietnamese nationals.

Two of the three crewmen seriously injured were also Vietnamese, while the third was an Indonesian national, said a statement from the Rescue Coordination Centre New Zealand (RCCNZ) Thursday.

Altogether seven crewmen were injured and they were aboard the US research vessel Nathaniel B. Palmer en route to the US Antarctic research base at McMurdo, said the statement.

The three seriously injured men had been hospitalized on the vessel, but were reportedly stable, said the statement.

"All three are described as having second and third degree burns, with two having burns to 30 percent and 50 percent of their bodies respectively," said the statement.

However, the RCCNZ could not confirm which nationals had which injuries.

The other four injured crewmen -- two Vietnamese and two Indonesians -- were reportedly in "good spirits" and were up and moving around.

The men were rescued after the Jeong Woo 2 caught fire while fishing in the Ross Sea on Wednesday.

"The Jeong Woo 2 is still ablaze and plans are for her sister ship, the Jeong Woo 3, to tow her outside Antarctic waters to minimize any potential effect on the Antarctic environment," said the statement.

It was still too dangerous to attempt to recover the bodies of the three dead crewmen.

"Surviving crew have confirmed that the men did not make it out of the vessel's accommodation block after the fire started early on Wednesday morning," it said.

The Nathaniel B. Palmer was expected to reach McMurdo at around 8 am Friday (New Zealand time), weather and ice conditions permitting.

A US Air Force C-17 Globemaster aircraft was scheduled to land at McMurdo at about 2 am Friday to evacuate the injured men back to Christchurch hospital as soon as possible.

The statement said any investigation into the cause of the fire would be a matter for the Korean maritime authorities.

The 51-meter Jeong Woo 2 was fishing in the Ross Sea, about 2, 000 nautical miles (3,704 km) southeast of New Zealand and about 600 km north of McMurdo Station, when it issued a distress call just before 3 am Wednesday.

The 51-metre-long (155 feet) the Republic of Korea (ROK) fishing vessel, Jeong Woo 2, burns in the Southern Ocean near the Antarctic ice shelf around 2,000 nautical miles (3,700 km) south east of New Zealand Jan 11, 2012. [Photo/Agencies]