In a barren landscape covered in ash, homes were almost completely submerged, and a truck had only the top of the driver's seat visible.
At least 14 people were killed and dozens injured in the eruption on Saturday (December 4), the disaster mitigation agency (BNPB) said.
Fifty-six were injured and 1,300 have been evacuated.
In the Sumberwuluh area, thick, grey ash coated damaged houses, while volunteers tried to turn away motorists who wanted to go back to their homes near Semeru, a Reuters witness said.
Heavy rain is expected for the next three days, which could complicate evacuation efforts, a meteorological agency official said late on Sunday.