The Tower Hill station was closed after the battery explosion but has since then been reopened for public.
A phone charger exploded at London's Tower Hall Tube station on Tuesday, causing panic and fear to spread among the masses.
The panic sparked a stampede as concerned commuters ran off the train.
The force said the incident was "not suspicious", adding that the fire is believed to have been caused by a mobile phone charger overheating.
British Transport Police tweeted that the incident is not suspicious.
Images appeared to show the item on fire in a train carriage.
The explosion occured on a District Line train which was heading towards Ealing Broadway from east London, reports said.
British Transport Police tweeted: "Officers have been called to Tower Hill station following a fire alert".
Meanwhile, the services on Circle Line and District Line were also disrupted.
This is the second incident of blast in September this year.