Tokyo police have arrested four people over an attempted theft at a multistory parking lot at Haneda Airport in the capital¡¯s Ota Ward in January.

The Metropolitan Police Department suspects that the four mistook the victim, a man in his 20s, for their intended target of a failed robbery involving about ?190 million in cash that took place at the same airport parking lot soon afterward.

Those arrested include Yoshito Koyama, 20, whose address and occupation are unknown and whom investigators believe was the group¡¯s leader. The other suspects are Hizuki Sugamori, 22, from Machida, western Tokyo, Taiga Kurihara, 20, also from Machida, and a 16-year-old boy.

The four are suspected of attempting to steal two travel bags containing a computer and other items from the man in his 20s on the third floor of the parking lot in the early morning hours of Jan. 30.

About two minutes after the incident, a group of four people transporting about ?190 million in cash was assaulted on the same floor of the parking lot, although nothing was stolen. As the man in his 20s had nothing to do with the group carrying the cash, the investigators believe that the suspects mistook him for their intended target.

Two of the four cash-carrying people later flew to Hong Kong, where they were robbed of about ?51 million in cash. One of the two was arrested with others by local authorities and was later indicted.

About 2? hours before the Haneda incidents, suitcases containing about ?420 million in cash were stolen on a street in the Higashiueno district in Tokyo¡¯s Taito Ward.

Jinryu Kano, 21, whom investigators believe directed the operation, and others have been arrested and indicted over that incident. Kano is a senior member of a group affiliated with Yamaguchi-gumi, a major organized crime group.

The victims in both incidents were transporting cash from gold transactions and other business dealings to Hong Kong. Police are investigating possible connections between the two cases.