The attacks were clearly aimed at discouraging non-Croat refugees from returning to settlements south of Mostar, human rights workers said.
Five houses once inhabited by Muslims were destroyed in Stolac on Sunday night and another house was torched on Monday, said Major Tony White, spokesman for the Nato-led peace force.
Three houses in nearby Kukavac were also destroyed on Sunday, two homes belonging to Serbs were razed in Stolac at the weekend and explosions had damaged a house in the village of Prebilovci on Monday, Major White said.
The reports coincide with an alarming rise in expulsions of Muslims from Croat-controlled western Mostar over the past three months.
Groups of armed men have been systematically evicting the remaining Muslims from western Mostar and seizing their flats, according to United Nations relief workers and international police monitors.
Mostar is strictly divided into Croat and Muslim sectors since a 10-month Muslim-Croat war ended in 1994. Croat authorities have failed to put a stop to the expulsions despite repeated pleas from Western diplomats.