The inquiry will focus on whether building regulations were enforced and whether officials had planned adequately for natural disasters.
At least 290 people are now known to have died in Saturday’s disaster and more than 300 are still missing.
About 2,700 residents are living in shelters.
Some areas remain without water and electricity, and police reinforcements have been sent in to deter looters.
Meanwhile, rescue teams continue the grim search for victims buried under piles of debris.