EDMONTON - Damaged equipment from Canadian Natural Resources Ltd.'s Horizon oilsands project may be removed for testing after a fire that injured five workers.

Officials say wreckage and ice prevented investigators from getting into the site of the Jan. 6 explosion until late last week.

Barrie Harrison of Alberta Occupational Health and Safety says staff have started assessing the extent of damage to key parts of the upgrader.

He says some of the massive parts may have to be removed for tests before repairs can begin and the site remains under a stop-work order.

Earlier this month, the Calgary-based oil and natural gas giant (TSX:CNQ) declared it could not meet its January crude shipments from the damaged facility.

Company officials were unavailable for comment on the investigation or the status of February crude shipments.