Sabah state tourism minister Masidi Manjun laid a wreath of flowers at a monument in Mount Kinabalu in Sabah, where all the victims died.
They were among the 195 people who were scaling the 4,096-metre peak when the 5.9 magnitude quake struck and dislodged boulders above that rolled and crushed the hikers.
Dozens of trekkers were injured in the incident.
Masidi also led a tree-planting event in memory of the four mountain guides who were among the 18 victims.
Relatives of the victims and some survivors attended the ceremonies.
- DPA