Barack Obama says no act of terror can shake 'strength, resilience of our British ally'

Former United States President Barack Obama on Thursday expressed his condolences and condemned Wednesday's atrocities in the heart of London.

Police have confirmed that Westminster Bridge has re-opened less than 24 hours after the terrorist attack. At least four people were killed and dozens more were injured after a vehicle drove into pedestrians before crashing into the gates at the Houses of Parliament.

One of the victims has been identified as US tourist Kurt Cochran. His wife Melissa was also seriously injured and is in hospital.

A statement from Melissa's family said:

"Our family is heartbroken to learn of the death of our brother - and son-in-law - Kurt W. Cochran. Kurt was a good man and a loving husband to our sister and daughter, Melissa. They were in Europe to celebrate their 25th wedding anniversary, and were scheduled to return to the United States on Thursday. Melissa also received serious injuries in the attack, and is being cared for in the hospital. We express our gratitude to the emergency and medical personnel who have cared for them and ask for your prayers on behalf of Melissa and our family. Kurt will be greatly missed, and we ask for privacy as our family mourns and as Melissa recovers from her injuries."

ISIS have claimed responsibility for the attack, describing the terrorist as a "soldier of Islamic State," according to Amaq news agency.

UK Prime Minister Theresa May had earlier confirmed in the House of Commons that police are working under the assumption that the attacker was "inspired by Islamist ideology."

No other details have been released about the assailant who was shot dead outside the Parliament except that he was British-born and previously investigated by MI5 for violent extremism.