Two dead, including a teenage girl, after boats carrying students capsize near the site of a new US military base in Japan

Two boats carrying 21 people capsized Monday off Henoko, a controversial relocation site for a U.S. military base off the southern Japanese island of Okinawa, throwing them all into the water and leaving two of them dead, officials said.

The Japan Coast Guard said 18 of them were students from a Kyoto high school on two ships, 10 on the Heiwa Maru and eight on the smaller Fukutsu, to observe the Henoko area as part of its peace education program.

Coast guard rescuers pulled all 21 people from the water, but a 17-year-old student and the captain of the Fukutsu were later pronounced dead, authorities said. Two people were injured but their lives are not in danger.

The teenager was wearing a life jacket at the time of her death, a coast guard official told Agence France-Presse. A high surf advisory was in effect for Okinawa at the time of the accident, which occurred around 10 a.m., the official said.

The cause of the accident is under investigation, according to Coast Guard officials.

The boats were approximately half a mile east of Henoko when they capsized. Despite the wave warning, the water was not very rough and there were no signs of the boats colliding, authorities said.

Persistent protests and lawsuits between Okinawa and Tokyo have delayed a plan to relocate the US Marine Corps Air Station Futenma from a populous neighborhood on the island for nearly 30 years.

Many local residents have opposed the US military presence for years, following a avalanche of crimes and accidents involving US soldiers and base personnel.

Last July, police said two us marines in Okinawa were under investigation for alleged violations.

Henoko is a popular destination for activists opposing the relocation, but the students did not protest, officials said.

Okinawa is home to about half of the 50,000 U.S. troops stationed in Japan under the bilateral security pact. Many Okinawans complain about the risks of accidents, noise, pollution and crime associated with US bases.