Red-rumped swallow – Cecropis daurica
The red-rumped swallow (Cecropis daurica) is a small passerine bird in the swallow family. It breeds in open hilly country of temperate southern Europe and Asia from Portugal and Spain to Japan, India and tropical Africa. The Indian and African birds are resident, but European and other Asian birds are migratory. They winter in Africa or India and are vagrants to Christmas Island and northern Australia. Red-rumped swallows are somewhat similar in habits and appearance to the other aerial insectivores, such as the related swallows and the unrelated swifts (order Apodiformes). They have blue upperparts and dusky underparts.

This is the sound it makes
Recording by Anon Torimi from Xeno-Canto