Koraput: The district administration on Tuesday sought the help of army to assist in the rescue operation on two earthmover drivers, who had been trapped under the heap of boulders since May 31 at a stone quarry near Bariput in the district.

The Odisha Disaster Rapid Action Force and the National Disaster Response Force teams have failed to rescue the trapped duo - Ghanashyam Guru and Sanjay Das.

"A team of army officials belonging to their engineering battalion stationed at Ranchi in Jharkhand will be reaching the district shortly and take stock of the situation," said Koraput collector K. Sudarshan Chakravarthy.

He said that more than 150 personnel, including technicians, belonging to various agencies have been pressed into the rescue operation, but still there is no headway.

"The work is not as easy as it appears. While it is difficult to shift the huge boulders, there is fear of boulders running down the hill from the top - if any of the boulders is dislodged. Hence, we can't take a chance," the collector said, who reached the spot around 6am on Tuesday to take stock of the situation.

The administration has pinned hope that once the army personnel reach the spot it will be easy to rescue the trapped drivers as they are possessed with higher engineering skills and sophisticated equipment.

For the arrival of the army officers, the administration has constructed a temporary helipad at the accident site.

Around 6pm on Thursday, the accident took place when the two drivers were removing boulders from the quarry.

The stones extracted from the quarry were used at the Telangiri irrigation project. The dam of the project lies at a distance of about 500 metres from the quarry.

In another development, officials said as six days had been passed since the incident took place, there was least chance that the trapped drivers were still alive. "But, still we can't jump to any conclusion till we wind up our rescue operation," an official said.