LONDON: Seven of the 11 people arrested since the Westminster attack have been released with no further action, police have said.

The Metropolitan Police said two men remain in custody, while two women have been released on bail until late March.

Police are trying to establish whether attacker Khalid Masood acted alone, BBC reported.

Meanwhile, the Saudi Arabian government has confirmed that Masood worked in the country as an English teacher in two different spells between 2005 and 2009.

Four people were killed and 50 injured after Masood drove his car into people on Westminster Bridge and stabbed an officer guarding Parliament.

PC Keith Palmer, 48, died of his wounds. Masood was shot dead by police.