Emergency services were alerted to a blaze on Grinshill just before 7pm on Friday evening, and within 40 minutes calls were made to a second fire also on the picturesque hill.
Firefighters said they also had call-outs the previous Saturday to the area.
Both fires on Friday were brought under control by 8pm.
Shropshire Fire and Rescue Service said the first involved hedgerow and undergrowth that had multiple seats of fire. The second involved a bonfire.
A spokesman for Wem Fire Station said: "Unfortunately, due to the incidents last Saturday and both incidents we attended on Friday in Grinshill, it is believed they have been started deliberately.
"West Mercia police have been informed and, if you have any information please contact the police or our fire control."