LONDON (AP) — Khalid Masood, who attacked Britain's Parliament, killing four people and wounding some 50, was born Adrian Russell Ajao, London's top counterterror officer said Friday.

Mark Rowley revealed the name in a briefing outside Scotland Yard in which he also announced two more "significant" arrests had been made. That brings the total number of people in custody for the Wednesday attack to nine.

"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," Rowley said. "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."

The 52-year-old attacker was born in southeastern England and had most recently been living in the central city of Birmingham.

Masood drove his car into crowds of people on Westminster Bridge on Wednesday afternoon, killing three and wounding some 50, before stabbing a police officer to death at the Houses of Parliament. He was shot dead by police.

Rowley said two police officers targeted in the attack have significant injuries. Two other people also remain in critical condition, one with life-threatening injuries.

The latest victim, who died in the hospital on Thursday, was 75-year-old Leslie Rhodes from Streatham, south London.