The fire broke out at a factory owned by a unit of Nippon Steel plant near Haneda airport in Kawasaki city, reported BBC.
One Twitter user wrote (in Japanese): "I was about to board my flight at a gate at Haneda airport when I realised many people were looking outside the window so I went over and realised there was a huge fire.
"Our flight was delayed by 15 to 20 minutes, and the pilot said it was partly because of the fire (but no major issue).
"Because of recent news about explosions in Yokosuka and China, I started wondering if it was something similar and people were looking nervous.
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It was the second large fire to break out in Japan on Monday, following a blast at a US military base in Sagamihara which has been extinguished.