LONDON: Seven of the 11 people arrested since the Westminster attack have been released, police sources have said. The Metropolitan Police said two men still remain in custody, while two women have been released on bail until late March. Police are trying to establish whether the attacker Khalid Masood acted alone, British media 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 were injured after Masood drove his car into people on Westminster Bridge and stabbed an officer guarding the Parliament. Masood was shot dead by police.