As part of the investigation of the London Underground train, the British Police said they have arrested a suspect.
The 18-year-old man was arrested by Kent Police in the Area of Dover.
The Police have described the arrest as “significant”.
“Although we are pleased with the progress made, this investigation continues and the threat level remains at critical,” police said.
The man is in custody at a local police station and will be transferred to a south London police station in “due course”.
Parsons Green station was attacked on Friday morning after a bomb was detonated.
Thirty persons are reported to have been taken to the hospital for treatment and no death recorded so far.
“This arrest will lead to more activity from our officers,” police said.
“For strong investigative reasons we will not give any more details on the man we arrested at this stage.
“This investigation continues and the threat level remains at critical,” the statement added.
ISIS has claimed responsibility.
This is the fifth attack and the less severe Britain has suffered on six months.
On March 22, a man drove a car into pedestrians on Westminster Bridge, then crashed it into the perimeter of the Palace of Westminister.
He then entered the grounds of the Palace of Westminster, stabbed a police officer who confronted him, then was shot himself.
Six people, including the attacker, died and 50 people were injured
The attack was treated as an act of terrorism
On the same day in May, an attack in Manchester left 22 people dead and 59 injured after a male suicide bomber targeted children and young adults at the end of a concert at the Manchester Arena by US singer Ariana Grande.
On the 3rd of the following month, an attack in London left seven people dead and 48 injured. A white van hit pedestrians on London Bridge before three men got out of the vehicle and began stabbing people in nearby Borough Market. The suspects were shot dead by police minutes later.
On June 19th, A group of Muslim worshippers were hit when a van mounted the pavement and drove into them in Finsbury Park. The attack happened during the holy month of Ramadan when many people were in the area attending evening prayers. One man, who had fallen ill before the attack, died and nine other people were treated in hospital. A 47-year-old man has been arrested on suspicion of terrorism offences.
35 lives have been lost in all five attacks on Britain.
