A massive power blackout hit 350,000 households during a short period in central Tokyo on Wednesday afternoon, disrupting trains and bringing elevators to a halt, The Japan Times reported.

Tokyo Electric Power Company Holdings Inc. said the outage was likely caused by a fire at a Tepco facility in Niiza, Saitama Prefecture.

Economy minister Hiroshige Seko directed the utility to investigate the cause of the problem, and to take further actions to prevent any recurrence.

The municipal office advised residents not to open their windows. An official of the city of Niiza said cables at the Tepco facility had caught fire.