Indonesian authorities have found 12 bodies as they continue to search for survivors from a plane crash on Wednesday. The Russian-made jetliner crashed into the side of Mount Salak during a demonstration flight for potential buyers.

The search team used ropes to get to the wreckage through jungle terrain on near-vertical slopes. All 45 people aboard the plane are feared dead. Indonesia’s President Susilo Bambang Yudhoyono has visited relatives of the victims. Indonesia and Russia have agreed to work together on the recovery operation and to investigate the cause of the accident.

The Sukhoi Superjet-100 was carrying dozens of journalists and representatives from local airlines when it crashed into the side of the Indonesian volcano.