Two men already in custody for alleged possession of Ecstasy were served new arrest warrants Wednesday on suspicion of involvement in smuggling several hundred kilograms of stimulants into Japan from North Korea, bringing the total number nabbed in the smuggling case to seven, police said.

Tsunehiko Noto, 63, and Kiyoharu Shishikura, 50, who are both believed to be connected to a group affiliated with the Matsuba-kai underworld syndicate, are suspected, along with five other suspects, of smuggling the drugs on Oct. 9, 2002, police said.