Eight people were arrested by the UK police in aftermath of the terrorist attack in Westminster which killed four people and injured 40 others.
The police officials have searched six addresses in London, Birmingham and other places during the investigation, according to media sources.
The attacker, who drove his vehicle into pedestrians walking across Westminster Bridge, was shot dead by police officers.
The vehicle-ramming attack that occurred on Wednesday is reportedly linked to Islamic terrorism, media sources reported.
Commenting on the attack, UK Prime Minister Theresa May said: “This attacker, who was armed with a knife, then ran towards Parliament where he was confronted by the police officers who keep us – and our democratic institutions – safe.
“Tragically, one officer was killed.”
Following the attack, the British Parliament and London Eye Ferris wheel were placed on lockdown for few hours.
May added: “The location of this attack was no accident. The terrorists chose to strike at the heart of our Capital City, where people of all nationalities, religions and cultures come together to celebrate the values of liberty, democracy and freedom of speech.
“These streets of Westminster – home to the world’s oldest Parliament – are ingrained with a spirit of freedom that echoes in some of the furthest corners of the globe.”