
In this aerial image made from video, emergency workers help people to disembark a train near the Parsons Green Underground Station after an explosion in London Friday, Sept. 15, 2017. An explosion at a train station sent commuters stampeding in panic, injuring several people at the height of London's morning rush hour, and police are treating it as a terrorist attack. (Source: AP)

Smoke is seen coming out of items that were set in flames after an explosion occurred in an underground train in London Friday, Sept. 15, 2017. (Source: AP)

A woman reacts outside the Parsons Green tube station in London. (Source: Reuters)

An injured woman is led away at Parsons Green underground station in London. (Source: REUTERS)

People stand in the street near Parsons Green tube station in London. (Source: REUTERS)

Forensic investigators seeking for evidence next to a London underground tube at Parsons Green station in London. (Source:REUTERS)

Members of a bomb disposal squad stand in the street near Parsons Green tube station in London. (Source: Reuters)

Ambulances stand nearby to help the injured after an explosion took place on a tube train at Parsons Green subway station in London. (Source: AP)

Emergency personnel attending a victim at Parsons Green underground station in London, Britain, September 15, 2017. (Source: Reuters)

Fire Brigade officers stand inside a cordon, police say they are treating the incident as a terrorist attack. A bucket wrapped in an insulated bag caught fire on a packed London subway train Friday, sending commuters stampeding in panic at the height of the morning rush hour. (Source: AP)

An injured woman is being attended by the officers at Parsons Green underground station in London, Britain, September 15, 2017. (Source: REUTERS)

A underground tube is held after an explosion took place in a train at Parsons Green station in London. (Source: Reuters)