Tachymarptis melba
Only swift in the region with white underparts divided by breastband. Upperparts brown. Distinctly bigger than Swift, with robust build and powerful flight. Tail short with rather shallow fork. Wing-action slower than Swift, with each beat discernible. May give Hobby-like impression at a distance .
Seldom heard except in breeding season. Call a long, hard, trilling note, reminiscent of Temminck's Stint . Also a short, cut-off pju pju pju used as alarm call.
Wikipedia: map (se also Xeno-canto below)
Birdlife ecology