Eight bodies washed up on the coast of Japan in a small wooden boat Monday, the Japan Coast Guard announced. Officials believed the people inside the boat may have been from North Korea due to a pack of cigarettes found among their belongings, according to the Japan Times.

Officials could not confirm yet when the eight people died, as portions of the bodies found were just skeletons. Authorities also had not yet determined the boat’s country of origin, the Japan Times confirmed. It remained unclear what their cause of death was, but authorities said it appeared they may have been fishermen whose boat ran into trouble. The Japan Coast Guard said it was actively working to confirm the nationalities of those on board the boat, Reuters reported.

The discovery of eight bodies came less than a week after a separate group of eight men were found on Japan’s northern coast after they said their boat from North Korea broke down and washed ashore. The men, in their 30s and 50s, reportedly said they departed from North Korea a month ago on a fishing expedition. The men also reportedly told officials they wanted to go back to North Korea, a claim authorities said they were investigating.

“We are investigating men and we will respond appropriately together with related organizations,” Chief Cabinet Secretary Suga Yoshihide said in a press conference, noting that they were also investigating the possibility of the men being North Korean agents.

A mere two days later, the bodies of two unidentified men were found alongside broken parts of a wooden boat along the coast of Sado Island in Japan. Reports suggested the men were from North Korea. They were found with a pack of cigarettes with Korean writing, other personal belongings and life jackets that had Korean lettering on them, authorities said. Their cause of death had not yet been determined.

It was unclear whether any of the men were involved in any of the incidents were defecting from North Korea, though such defections have made international headlines in recent days. A North Korean soldier defected to South Korea earlier in November by running across the border between the two countries during a military training exercise, a daring dart for freedom that was captured on film.

The 24-year-old, identified only as Oh, was shot by North Korean soldiers as he crossed the border but made it 150 feet into South Korea and was taken into the country for treatment. Oh reportedly suffered from a variety of ailments in addition to gunshot wounds, including two types of roundworms, hepatitis B and inactive tuberculosis. The man was also suffering nightmares he would be sent back to North Korea, his doctor said.