Where in the world?
The flag of Burundi has a white field with a red diagonal cross, green and red areas, and a white disk with three red stars in the center.

Burundi

Population: 11,890,781

Region: Africa

Subregion: Eastern Africa

Capital: Gitega

Top Level Domain: .bi

Currencies: Burundian franc

Border countries

The flag of the Democratic Republic of the Congo has a sky blue field with a yellow star in the upper hoist-side corner and a diagonal red stripe with a thin yellow border from the lower hoist-side to the upper fly-side.

Congo (Democratic Republic of the)

Population: 89,561,404

Region: Africa

Capital: Kinshasa
The flag of Rwanda has three horizontal stripes of blue, yellow, and green with a sun in the top right corner.

Rwanda

Population: 12,952,209

Region: Africa

Capital: Kigali
The flag of Tanzania has a green and blue field with a black diagonal stripe bordered by yellow.

Tanzania, United Republic of

Population: 59,734,213

Region: Africa

Capital: Dodoma