Swallow? Swift?

A crumpled looking tail, a dark face. Can't see the breast colour. I'm unsure wha this bird is - but I've never seen a swift with white splotches around its posterior. Or a dark faced Swallow. Is it an immature swallow? There were no other swifts evident at the time and I didn't hear any swift's screams.

So I'll guess it's a young swallow. Right/Wrong? If you know please comment with info?

Done