Two NTT employees were arrested Tuesday on suspicion of helping members of a leftist extremist group illegally obtain information on members of a rival faction, police officials said.

The suspects -- Sakae Igarashi, 42, of NTT East and Takeshi Yamamoto, 39, of NTT Mobile Communications Network (NTT DoCoMo) -- acted on the instruction of extremists belonging to the Kakumaru-ha, a leftist group, according to the Metropolitan Police Department.

Later in the day, police investigators searched for evidence at the NTT offices where the suspects worked. The MPD suspects several other NTT group employees may have been involved in the information theft.