Seoul confirmed the seizure of a South Korean chemical tanker by Iranian authorities in the waters off Oman, and demanded its immediate release. 

Several Iranian media outlets, including Iranian state TV, said the Guards navy captured the vessel for polluting the Gulf with chemicals. The semi-official Tasnim news agency published pictures showing what it identified as Guards speed boats escorting the tanker HANKUK CHEMI, which it said was carrying 7,200 tonnes of ethanol. 

It said the vessel’s crew members had been detained and included nationals of South Korea, Indonesia, Vietnam and Myanmar. It said the tanker was being held at Iran’s Bandar Abbas port city. The ship had 20 crew members, according to South Korea’s foreign ministry. 

The U.S. Navy’s Bahrain-based Fifth Fleet was aware and monitoring the situation, spokeswoman Rebecca Rebarich said in response to a Reuters query. 

Iranian authorities have yet to comment on the incident, which comes ahead of an expected visit by South Korea’s deputy foreign minister to Tehran. 

Iranian foreign ministry said on Monday that the visit would happen in coming days and would discuss Iran’s demand that South Korea release $7 billion in funds frozen in South Korean banks because of U.S. sanctions. 

NUCLEAR DEAL 

The United States re-imposed sanctions on Iran in 2018 after Washington withdrew from Tehran’s 2015 nuclear deal with six major powers, under which Iran agreed to curb its nuclear work in exchange for lifting sanctions. 

Iran has retaliated by bypassing the restrictions of the deal step-by-step. In a move that could complicate efforts by U.S. President-elect Joe Biden to rejoin the deal, Tehran said on Monday it had resumed 20% uranium enrichment at its underground Fordow nuclear facility. 

British firm Ambrey said the South Korean-flagged vessel, owned by DM Shipping Co, had departed from the Petroleum Chemical Quay in Jubail, in Saudi Arabia, before the incident. 

Another maritime security firm, Dryad Global, said on its website the chemical tanker had “likely been detained by Iranian forces” in the Strait of Hormuz while inbound to Fujairah in the United Arab Emirates. 

In early 2019, Iran heightened tensions in the world’s busiest oil waterway by seizing British-flagged tanker Stena Impero, two weeks after a British warship had intercepted an Iranian tanker off the coast of Gibraltar.