A North Korean fishing vessel collided with a Fisheries Agency patrol boat Monday morning inside Japan’s exclusive economic zone off the coast of the Noto Peninsula in Ishikawa Prefecture. About 60 fishers were thrown into the sea, according to media reports.

All members were rescued unhurt, the reports said. The surviving members were expected to be handed over to North Korea according to an international treaty.

The collision took place in an area known as Yamatotai, located 350 kilometers northwest of the Noto Peninsula, where illegal fishing by North Korean fishers is rampant. The fishing boat sank at around 9:25 a.m., while the Fisheries Agency’s 1,300-ton patrol boat, the Okuni, was able to operate on its own, according to the Japan Coast Guard.

Satoshi Kuwahara, an enforcement division chief at the Fisheries Agency, told reporters Monday afternoon that the two boats collided at 9:07 a.m. when the patrol boat was warning the fishing boat to leave the area.

Agriculture minister Taku Eto told reporters Monday afternoon the North Korean vessel collided with the patrol boat after making a sharp turn. The cause the maneuver is under investigation.

Yamatotai, an area rich with plankton, is a fertile and important fishing ground for crabs and squid fisheries that has been frequently targeted by illegal North Korean fishers.

The Fisheries Agency and the coast guard have bolstered cooperation and increased their crackdown on the surge in illegal fishing in recent years.

The agency’s patrol boats issued warnings to 5,315 North Korean boats illegally operating in the area in 2018, and 5,191 vessels in 2017. The rise of illegal fishing by North Korea is attributed to its sanctions-crippled economy and severe food shortages.

Between May and early August, Fisheries Agency patrol boats issued warnings to 498 North Korean fishing vessels telling them to leave Japan’s exclusive economic zone. Of those 498 incidents this year, patrol boats sprayed 121 boats with water canons and confiscated fishing goods from 12 boats.

The coast guard, meanwhile, said it warned 1,016 North Korean ships and used water cannons against 189 vessels operating illegally in the Yamatotai area between late May and Monday morning.

The area also became a point of friction late August when a crew member of a high-speed vessel believed to belong to North Korea used a rifle to threaten a coast guard patrol boat. The government issued a protest to North Korea, which counterclaimed it was the Japan Coast Guard that made an “illegal intrusion” into its exclusive economic zone.

“This is an outrageous matter,” Ishikawa Gov. Masanori Tanimoto said at the time. “We hope the central government resolutely deals with it.”

In December 2001, a North Korean spy boat sank after a gunfight with a coast guard patrol boat in the East China Sea off the coast of the Amami Oshima island in Kagoshima Prefecture. In October 2006, a Japanese fishing boat and a North Korean cargo ship collided in the Tsushima Strait.

In addition, a wooden North Korean boat made its way to an uninhabited island in Hokkaido in November 2017. The crew members were deported after they were arrested on a charge of stealing an electric generator.

Information from Kyodo added.