Search crews are slowly making progress on a remote and dormant volcano in Indonesia, recovering the remains of victims of a deadly and mysterious plane crash.

More bags containing body parts arrived in the Indonesian capital, Jakarta Saturday, while clearer weather allowed crews to expand their search of the wreckage site on Mount Salak. Helicopters have also been brought in to aid the recovery effort.

Crews say the damage to the plane and to the victims is so severe, they will need to use DNA to identify the remains. Outside the hospital where the remains were sent, relatives of the victims waited anxiously, some even expressing hope that their loved ones might still be found alive.

Officials say all of the up to 50 passengers on board likely died when the Russian jet slammed into a nearly vertical cliff of Mount Salak at nearly 800 kilometers per hour Wednesday.

The doomed 100-seat Sukhoi Superjet 100, which was on a promotional sales tour, took off from Jakarta's Halim Airport shortly after 2 p.m. Wednesday with an entourage of prospective buyers, journalists and crew. It was expected to return in less than an hour. But the plane dropped in altitude from 3,000 to 1,800 meters and lost contact with air traffic control at Mount Salak, which is 2,200 meters high.

Authorities say it is not clear why the plane requested to descend or whether air controllers approved the maneuver.

Indonesian search and rescue agency spokesman Gagah Prakoso told the Associated Press a team has also been assigned to find the plane's so-called black box, which should have recorded critical flight information.

The Sukhoi Superjet 100 plane, built by Russia in a move to boost its civil aviation industry, was on the second of two demonstration flights when it disappeared in the remote Bogor region.

The jetliner is currently in use with Russia's largest carrier, Aeroflot, and the Armenian carrier, Armavia.