A man believed to be a "bosozoku" hot-rodder gang leader died Friday of wounds inflicted in an apparent attack by rivals.

Kodai Kitajima, 19, and his friend, Tadafune Kakizaki, 24, were found lying in a pool of blood at around 1 a.m. Friday in a parking lot at Mizumoto Park in Tokyo's Katsushika Ward, police said.

Kitajima, who had head injuries and two stab wounds to the buttocks, died shortly after he was found. Kakizaki reportedly sustained serious wounds to the head and chest.

Police suspect the two were attacked by a rival motorcycle gang and said witnesses reported seeing several vehicles speed away from the parking lot before the two were found.

Forty minutes before the victims were found, residents in an apartment complex about 4 km from the park said they saw a group of about 10 people attacking two men with what appeared to be wooden swords and then carry them away in their cars.