Two people died after two boats used in protests against a U.S. military base relocation capsized off the coast of Henoko in Okinawa Prefecture on Monday morning.

The incident occurred around 10:10 a.m. local time near the Henoko district of Nago City. The vessels, named Heiwa Maru, carrying 12 people, and Fukutsu with nine aboard, overturned in waters where construction is underway for a new runway at the planned replacement for the U.S. Marine Corps Air Station Futenma. All 21 people on board, including 18 students from Doshisha International High School in Kyoto, were rescued by the Japan Coast Guard's 11th Regional Headquarters in Naha.

The victims were identified as a 17-year-old female student from the school and the 71-year-old captain of the Fukutsu. Four others were hospitalized, with at least two suffering injuries, while more than a dozen sustained non-life-threatening wounds. No one remains missing.

The students were in Okinawa from March 14 to 17 as part of a peace education program. Eighteen participated in a "Henoko course," boarding the protest boats operated by civic groups to observe reclamation work for the base project. The Coast Guard is investigating the cause, with weather reported as clear despite a high surf advisory.

Okinawa Governor Denny Tamaki expressed grief, stating, "It has become a tragic accident. I am heartbroken."

The Henoko project aims to move the Futenma base from a crowded area in Ginowan to the less populated northern coast, addressing longstanding local concerns over noise, aircraft crashes, and environmental damage. Okinawa hosts about 70% of U.S. military facilities in Japan, fueling ongoing protests that have delayed construction.

This marks the second boat incident near the site in a week, following a non-protest work boat capsize on March 9 that resulted in no injuries.