The eruption on 4:00 p.m. Tuesday of local time killed two people and injured five others.
"If analyzed from the victims evacuated, (it is found that) they entered from one gate, that is Cemoro Lawang gate. There are many gates to Mt. Bromo, so it is possible that there are more other victims," Andi Susetyo, SAR team coordinator in the Mt. Bromo eruption, was quoted by Detikcom online news service as saying.
He also said that three more people were reported to have been lost but he did not confirm that they were killed or not.
"It will be proved if we have been searching in the top (of the volcano)," he said, adding that his team is waiting for the safer time to search more victims.
Meanwhile, the head of volcanic observatory in the Indonesia's west region, Mas Atje Purbawinata, said that Mt. Bromo until Wednesday still sprayed white haze, but the height of the haze declined to only 25 meters after it reached 3,000 meters on Tuesday.
He said that the volcano did not send signals that it would erupt, so the victims did not have much time to save themselves.