Bulgaria
Continuing through the Bulgarian part of Znepolje curving around the eastern side of the Ruy mountain, the river, now called Erma, is also known as Transka reka after the town of Tran, a regional centre of this area. The Erma passes close to the villages of Glavanovtsi and Turokovtsi, where it turns north, running through Tran. After Tran, the Erma cut the famous gorge Transko zhdrelo ("Gorge of Tran"). After the gorge, Erma flows through the Bulgarian part of the village of Petachinci. Erma receives its major tributary, the Yablanitsa, right before it re-enters Serbia after 26 km of flow in Bulgaria. The river crosses the border for the second time about a kilometer after (Petachinci)