The Cheonghai unit, which includes South Korean special forces, arrived at the strait on Tuesday aboard the 5,000-ton destroyer Choi Yong, according to the South Korean Defense Ministry.
Founded in 2009 as South Korea’s first foreign anti-piracy force, the Cheonghai unit has been deployed in the Gulf of Aden, between Somalia and Yemen, to help maintain the free movement of South Korean ships through the region.
Roughly a year ago, Unity’s area of operations expanded to include the Gulf of Oman and the Persian Gulf, some 1,800 kilometers (1,118 miles) to the east, as tensions in the area escalated.
The expansion came after officials in the United States, a key ally of South Korea, requested assistance in protecting international shipping in the region, even though Seoul had fallen short of joining a US coalition to protect the road.
Tensions rose in the Persian Gulf last week, near the first anniversary of the fatal US strike on Qassem Soleimani, Iran’s top military commander.
Then, on Monday, Iranian boats detained a South Korean-flagged chemical tanker, Hankook Shimi, as it crossed the Strait of Hormuz, the narrow entrance to the Persian Gulf from the Arabian Sea.
The South Korean Foreign Ministry said five South Koreans were among the 20 civilian sailors on board the vessel.
South Korean Foreign Ministry spokesman Choi Young-Sam said Tuesday that the government in Seoul is in close contact with its Tehran counterparts and is trying to secure the release of the sailors and the ship.
There was no indication that the Zhonghai unit would conduct a rescue operation, as the Ministry of Defense said it would advise other ships flying the South Korean flag in the area on safety.
However, the unit has carried out rescue operations for South Koreans in the region before – most notably in 2011, off the coast of Somalia. In this action, commandos from the Zhonghai unit stormed a South Korean tanker that had been hijacked by a gang of Somali pirates with its crew of 21.
The South Korean Defense Ministry stated that the commandos killed eight pirates and captured five others. None of the tanker crew died.
The government said the Chunghai unit released South Korean nationals who had been captured by pirates on a merchant ship flying the Singapore flag in 2012 and supported the evacuation of South Korean nationals from Yemen in 2015.