London Attack Update: Adrian Russell Ajao Was Birth Name Of Alleged ISIS 'Soldier,' Fourth Victim Dead

Scotland Yard’s top anti-terror officer Mark Rowley said in a press briefing Friday that the birth name of the attacker, who was identified as Khalid Masood, was Adrian Russell Ajao. Rowley also revealed that two "significant arrests" have been made overnight in the West Midlands and northwest and nine people have been taken into custody.

A 75-year-old man, identified as Leslie Rhodes from Streatham, South London, was a victim of the attack and died overnight at a hospital. Rhodes died Thursday evening after his life support machine was turned off. U.S. tourist Kurt Cochran, 54, was also a victim of the attack Wednesday. Aysha Frade, a London teacher, was also killed, according to the Guardian. Police officer, Keith Palmer, 48, was also stabbed and killed near the gates of the Parliament during the attack. Rhodes was the fourth victim in the attack.

During his briefing, Rowley also mentioned that almost 50 people were injured from the attack and 31 required hospital treatment. Among the victims who were being treated at hospitals, one was considered to have life-threatening injuries and two people were in critical condition. He also specified that the police have been focusing on understanding Masood's reasons to carry out the attack, his preparation and his associates. "Our determination is to find out if he acted totally alone inspired by terrorist propaganda or if others encouraged or supported him," Rowley said during the briefing.

The Islamic State group, also known as ISIS, claimed responsibility for the attack. Sharing a statement Thursday through its Amaq News Agency, ISIS wrote that "the attacker yesterday in front of the British Parliament in London was a soldier of the Islamic State," according to SITE Intelligence Group.

Rowley requested people to provide any kind of information related to the attacker in order to help with their investigation.

"We remain keen to hear from anyone who knew Khalid Masood well, understands who his associates were and can provide us with information about places he has recently visited. There might be people out there who did have concerns about Masood but did not feel comfortable for whatever reason in passing those concerns to us," he said, according to the Guardian.

Earlier on Thursday, the attacker was named as Khalid Masood by officials and Prime Minister Theresa May said in her address to the Parliament that he was born in Britain. May also said: "It is still believed the attacker acted alone and police have no reason to believe there are imminent further attacks on the public."

May mentioned that the suspect was known to MI5, the U.K.'s domestic intelligence agency.

"He was once investigated in relation to concerns about violent extremism," May said, while addressing the Parliament. However, May also revealed that the attacker was investigated "some years ago" and the "case was historic."