Investigative sources said Saturday Tokyo police are examining charred cables and other remnants of suspicious fires in at least six cases that have occurred along lines of East Japan Railway Co. in recent weeks. Arson is suspected in some cases.
As there were no signs of fires nearby, investigators are examining burned plastic bottles and tissue papers found near some of the scenes, the sources said, adding that someone may have thrown a plastic bottle containing a burning tissue.
A partially charred cable covering was found alongside tracks near a level crossing on the Keihin-Tohoku Line in Kita Ward on Aug. 16, according to the sources. A plastic bottle containing fluid that police believe is not oil, and some tissue paper was found nearby.
A week later, smoldering trash was found on tracks in Shinagawa Ward.
On Thursday afternoon, train operations were suspended briefly on the Yamanote, Saikyo and Shonan-Shinjuku lines after the driver of a Yama-note Line train traveling between Ebisu and Meguro stations reported that a power transmission cable and the cover of a communications cable about 20 meters away were on fire.
The fires did not affect power transmission, but the operator halted trains to conduct safety checks. Tokyo police suspect arson, the sources said.
A nearby security camera filmed a man who appears to be in his 30s close to the scene at about the time the fire started, sources said.
On the evening of Aug. 18, the trains on the Ome Line and three other lines in the Tokyo suburb of Tachikawa were suspended after an electricity cable caught fire under an elevated track of the Chuo Line.
And on Aug. 22, a cable fire was reported along a Chuo Line track in Nakano Ward.