They allegedly pelted stones at the bus, in which the Congress Minister was travelling, at Pangal town, sources said.
The activists, raising pro-Telangana slogans, tried to obstruct the bus but police dispersed them.
Undeterred by the protest, the Minister continued her yatra, which she launched on April 13.
During the yatra which will conclude on April 21, Aruna is publicising welfare schemes of the Congress government.