Less than two weeks after a terror attack in London's underground metro injured scores of people, a small cellphone battery explosion on the capital's underground caused panic Tuesday afternoon.

"Officers have been called to Tower Hill station following a fire alert," British Transport Police tweeted of the incident, which led to the station's evacuation, adding later, "Incident at Tower Hill station is not suspicious."

"Fire believed to have been caused by mobile phone charger overheating," said the tweet.

"The station is closed whilst officers and LondonFire responds," it added.

Transport for London (TFL) said some services had been suspended and there were severe delays due to the alert.

On Sept. 15, thirty people sustained mostly flash burn injuries when an improvised explosive device partially exploded in an underground train at the Parson Green station on the District Line.

British authorities declared the incident a "terror attack" and have since made seven arrests.

After the attack, the British government raised the terror threat level to "critical," meaning a terror attack is expected imminently.