A Russian fishing vessel caught fire near South Korea, killing four of its 25 crew members, before it was put out, The Moscow Times reported Friday morning.

The Russian crew was savedPhoto: TASS / Profimedia Images

The 769-ton vessel was carrying 100 tons of fish and seafood when the fire broke out around midnight off the coast of Ulsan, 300 kilometers southeast of the southern Korean capital of Seoul, according to Yonhap news agency.

The Ulsan Coast Guard said it rescued 21 crew members, two of whom received emergency medical treatment with minor burns. Four of the dead were initially considered missing.

Later, the Russian news agency RIA Novosti reported that their bodies were discovered by another Russian fishing vessel.

According to preliminary information, all 25 crew members were citizens of Russia.

So far, neither the South Korean nor the Russian authorities have commented on the possible causes of the fire, but the Prosecutor’s Office of the Russian Far East has announced that it has started an investigation.