Iran seized a South Korean-flagged oil tanker in the Strait of Hormuz on Monday hours before announcing it would increase its nuclear activities as tensions in the region mount in the final days of Donald Trump’s U.S. presidency.

The Islamic Revolutionary Guard Corps said it detained the Hankuk Chemi vessel at 10 a.m. Monday "due to repeated violations of marine environmental laws.”

It is the latest in a series of shipping incidents in the Persian Gulf, where several vessels have been attacked or seized in recent years.