Two tonnes of an explosive chemical compound -- the type that has been used in several terrorist attacks -- disappeared from Kinder Morgan somewhere between its Alberta and B.C. operations this fall, the RCMP has confirmed.

Two cubes of ammonium nitrate, weighing one tonne each, went missing while six thousand of the cubes were being transported from a plant in Redwater, Alta. to the company's North Vancouver facility sometime before Christmas. The product's final destination was Surrey.

Ammonium nitrate, commonly used as a high-nitrogen fertilizer, is sold to mining companies as an oxidizing agent for explosives. It has also been used in several terrorist attacks, including the 1995 Oklahoma City bombing, which killed 168 people and injured more than 600.

A compound called ANFO -- ammonium nitrate mixed with fuel or diesel oil -- is often used in improvised explosive devices or fertilizer bombs. ANFO was used in the Toronto 18 plot as well as the Oklahoma bombing.

Kinder Morgan says it launched an internal audit and recount after they discovered the missing product. The company believes it went missing in the stretch between Alberta and North Vancouver.

The disappearance was reported to B.C. RCMP just before Christmas, spokesperson Sgt. Tim Shields said.

"So far we haven't determined that there has been any type of criminal involvement or any type of theft," he told CTV News.

Shields said the company has been cooperating fully.

"They've been using considerable resources to follow the paper trial and conduct an internal inventory audit to determine if in fact there is any product that is actually missing or if this is just a tallying or inventory error."

Shields said the RCMP is taking the incident very seriously.

"We are erring on the side of caution because of the type of product were are talking about and what it could mean."

The ammonium nitrate was shipped to North Vancouver in 250 trucks and then moved to Kinder Morgan's Surrey warehouse.

Kinder Morgan released a statement to media Wednesday afternoon saying the trucks carrying the product were contracted to a third-party company and the compound itself is owned by another company.

Kinder Morgan said it is confident they have not had any security breaches. 

"Our warehouse is fenced, locked, guarded and secured with cameras," the statement said.

"As a precautionary measure, we reported the discrepancy to the appropriate authorities until the shipping and receiving documents could be reconciled. We anticipate that this review will show that the discrepancy is a paper accounting error."

Kinder Morgan is one of the largest pipeline and energy storage companies in North America, with more than 35,000 miles of oil pipelines. The company transports, stores and handles energy products including natural gas, refined petroleum, crude oil and ethanol.

With files from CTV British Columbia's Lisa Rossington