No one was hurt in both the incidents. Billboards and posters allegedly by Maoists were found in both the places, police said.
A forest range office at Mukkala in the Attapady region of Palakkad district, one of the main tribal hamlets in the state, was attacked and some of the furniture in the office damaged.
In the other incident, an office of "Vana Samrakshana Samithi" was vandalised by the outlawed activists at Kunhom at Vellamunda forest area in Waynad district.
It was significant that the attack came a few weeks after an exchange of fire between police and Maoists at Vellamunda. Security has been tightened in the areas, police said.
Wayanad had been a hotbed of Naxalite activities during the late 1960s and early 1970s and there had been instances of encounters with police.