Toys R Us may soon liquidate its U.S. operations, sources told CNBC.

One of those people cautioned, however, that the situation remains fluid.

Shares of Toys R Us debtholders Hasbro and Mattel saw their stocks fall in after-hours trade Thursday. Hasbro fell more than 3 percent, while Mattel stock declined nearly 5 percent.

Both toymakers previously said that the retailer's bankruptcy filing materially impacted their businesses.

In February, CNBC reported that the retailer was at risk of breaching the covenant on a $3.1 billion loan after a disappointing holiday season. Toys R Us' sales, traffic and profit all fell far short of what it had told lenders to expect.

While a terrible holiday season hurt their chances of recovery, some of the lenders have been aggressive in pushing for liquidation.

Toys R Us had already begun liquidation sales ahead of planned store closures.

The toy retailer filed for bankruptcy in September as it struggled with its $4.9 billion in debt. Under bankruptcy protection, Toys R Us tried to find the financial flexibility to reduce that debt.

Bloomberg first reported the news.