The death toll after the eruption of Indonesia's Semeru volcano has risen to 34, the Indonesian National Board for Disaster Management (BNPB) said on Tuesday, with help on the way to the affected area.

Semeru, the tallest mountain on Java island, erupted dramatically on Saturday, blanketing nearby villages in East Java province and sending thousands of people fleeing in panic.

The disaster swallowed entire homes and vehicles, blanketing villages such as Curah Kobokan in gray ash and leaving residents terrified of returning home.

"I'm traumatized. I asked my relatives if they were brave enough to go back to Curah Kobokan and they all said no, they'd rather sleep under a tree," said Marzuki Suganda, a 30-year-old who works at a sand mine in the area.

"When the eruption happened, I really thought I was going to die here."

Rescuers have been battling dangerous conditions since the deadly weekend eruption, searching for survivors and bodies in the volcanic debris, wrecked buildings and destroyed vehicles.

Search crews deployed dogs on Tuesday to aid the operation.

"The latest update from the ground... (is) 34 people died, 17 are missing," the disaster agency spokesperson Abdul Muhari told Agence France-Presse (AFP).

Almost 3,700 have been evacuated from the affected area, he added.

Dangerous rescue operation

Mt Semeru has remained active since Saturday, keeping emergency workers and area residents on edge.

There were three small eruptions on Tuesday, each spewing ash around a kilometer (3,300 feet) into the sky, authorities said.

The task for rescuers was made more difficult by the instability of the volcanic debris.

"What we are afraid of is the ground being cold outside but still hot inside," said police officer Imam Mukson Rido. "If it's hot inside, we must get away."

Officials have advised locals not to travel within five kilometers (3.1 miles) of Semeru's crater, as the nearby air is highly polluted and could affect vulnerable groups.

Indonesian President Joko Widodo said during a trip to the area Tuesday that the government will look into moving homes away because of the threat posed by the volcano.

"I hope after things calm down we can start both fixing infrastructures and think about the possibility of relocation from areas we believe to be dangerous," he told Indonesia's Metro TV.

"Earlier I got a report (that) there are around 2,000 houses that must be relocated."

Indonesia sits on the Pacific Ring of Fire, where the meeting of continental plates causes high volcanic and seismic activity, and the country has nearly 130 active volcanoes.