The man who killed four people near Briton’s Houses of Parliament on Wednesday was an English teacher working at the institution controlling Saudi Arabia’s civil aviation, according to a report.

The attacker, Khalid Masood, had been in the kingdom for two one-year periods and worked as an English teacher. His latest visit to Saudi Arabia was in March 2015.

“During his time in Saudi Arabia, Khalid Masood did not appear on the security services’ radar and does not have a criminal record in the Kingdom of Saudi Arabia,” the Saudi Embassy in London said in a statement on its Twitter account.

Masood was shot dead by British police on Wednesday after a rampage through Westminster.

Four people were killed and more than 50 people were injured when he ploughed his rented car into crowds of people on Westminster Bridge, before he crashed the car into the fence outside parliament.

Meanwhile, other reports on Friday said Masood was once investigated by MI5 for violent extremism but was discounted as a threat.

ISIS has claimed responsibility for the attack.

British police said that the assailant was found to have a history of violent offences. He also used the names Adrian Elms and Adrian Russell Ajao among other aliases.