Six American individuals were arrested on Friday in South Korea for attempting to send 1,600 plastic bottles loaded with rice, US dollar bills, and Bibles towards North Korea via the sea, as reported by the police.

According to a police officer who requested anonymity due to not being authorized to address media on the matter, the Americans endeavored to release the bottles into the sea from the front-line Gwanghwa Island with the intention of having them drift towards North Korean shores aided by the tides.

He said they are being investigated on allegations they violated the law on the management of safety and disasters.

A second South Korean police officer confirmed the detentions of the Americans.

The police officers gave no further details, including whether any of the six had made previous attempts to send bottles toward North Korea.

The practice of activists releasing plastic bottles or launching balloons carrying anti-North Korea propaganda leaflets across the border has been a longstanding source of tension on the Korean Peninsula.

North Korea expressed its anger at the balloon campaigns by launching its own balloons carrying trash into South Korea, including at least two that landed in the presidential compound in Seoul last year.

In 2023, South Korea’s Constitutional Court struck down a 2020 law that criminalized the sending of leaflets and other items to North Korea, calling it an excessive restriction on free speech.

But since taking office in early June, the new liberal government of President Lee Jae Myung is pushing to crack down on such civilian campaigns with other safety-related laws to avoid a flare-up tensions with North Korea and promote the safety of frontline South Korean residents.

On June 14, police detained an activist for allegedly flying balloons toward North Korea from Gwanghwa Island.

Lee took office with a promise to restart long-dormant talks with North Korea and establish peace on the Korean Peninsula.

Lee’s government halted frontline anti-Pyongyang propaganda loudspeaker broadcasts to try to ease military tensions.

North Korean broadcasts have not been heard in South Korean front-line towns since then.

But it’s unclear if North Korea will respond to Lee’s conciliatory gesture after it vowed last year to sever relations with South Korea and abandon the goal of peaceful Korean reunification.

Official talks between the Koreas have been stalled since 2019 when the US-led diplomacy on North Korean denuclearization derailed.