Maybe pakistani. In the UK, "Asian" is the code word for muslim.
I've noted they've been making a big deal that he is british-born.
Khalid Masood was his name.
From the Guardian:
Police name 52-year-old born in Kent as man responsible for attack in which three victims have died and seven more are critically injured
Highlighting that it's NOT immigrants that did this. No no no no no. The man was born in Kent.
There is nothing at all to fear from immigrants as a result of his actions.