Four males and three females were found dead Tuesday morning inside a station wagon in a mountain parking lot in Minano, Saitama Prefecture, police said.
Separately, two women were found dead in a car in Yokosuka, Kanagawa Prefecture, around 6:15 a.m.
Investigative sources said they believed that one of the women in the Yokosuka incident and one of the women found in Minano were among four women who tried to kill themselves in the town of Okutama, western Tokyo, on Oct. 4, but were stopped by police.