On 25 June 2018, Okinawan residents protested against the construction of a new airfield intended for the US military base in the United States. The activists, armed with placards and banners, went to sea on seventy boats and ships. Protesters urged the Japanese authorities to stop the expansion of the US military presence on the island. Some of the boats went to the guarded construction site, where they came across the Coast Guard patrol vessels. Some activists were arrested for entering a prohibited zone.