Commuters crammed onto the platform as a power outage brought Tokyo trains to a standstill.

Footage shows hundreds of passengers pressed shoulder to shoulder around ticket gates, escalators, barriers, and information boards inside Ueno Station on January 16.

Railway officials said the blackout disrupted the morning commute for an estimated 673,000 travellers after two major lines serving some of the city's busiest stations were forced to stop.

Trains on East Japan Railway's Yamanote and Keihin‑Tohoku lines were suspended for up to nine hours.

The outage was first detected around 3:50 am local time as staff prepared for the first trains of the day. The situation escalated shortly before 8 am, when a fire broke out on the tracks near Tamachi Station.

Although the flames were extinguished within 30 minutes, damage to signalling and electrical equipment kept services suspended throughout the busy morning rush.

The Yamanote Line serves major stations such as Shinjuku, which handles around 3.5 million passengers daily, while the Keihin‑Tohoku Line connects key hubs including Tokyo and Yokohama.