The Bank of England was forced to expand its emergency measures to tackle chaos in the bond market, adding inflation-linked debt to its purchases in an effort to stop “fire sale dynamics.”

The announcement on Tuesday came on the heels of a severe selloff that saw UK inflation-linked bond yields surging by the most on record.

“The beginning of this week has seen a further significant repricing of UK government debt,” the central bank said in a statement Tuesday. “Dysfunction in this market, and the prospect of self-reinforcing ‘fire sale’ dynamics pose a material risk to UK financial stability.”

UK government bonds opened higher after the BOE’s statement, with 10-year yields dropping as much as 4 basis points to 4.43%. The yield on equivalent inflation-linked securities fell 5 basis points.

The decision to buy index-linked securities is unusual for the central bank, which only bought conventional gilts during previous rounds of quantitative easing. The BOE said that it will allocate up to £5 billion ($5.51 billion) to conventional gilts and £5 billion to index-linked gilts.

That expands the scope of a bond-buying program, initially of long-maturity gilts. The emergency measure was intended to buy time for liability-driven investment funds — at the heart of the gilt selloff prior to the BOE’s intervention — to protect themselves from further spikes in yields. The central bank noted that they had made “substantial progress.”

“The BOE is clearly playing gilt selloff whack-a-mole,” said Antoine Bouvet, senior rates strategist at ING Groep NV. “The policy of consistently acting at the last minute without putting a more credible long-term plan in place is unnerving for markets.”

“With purchases still planned to end on Oct. 14, we’ll probably see another bout of market volatility around that day, or just after,” he added.

Inflation-linked debt was the worst hit in a bond market rout on Monday, with the yield on 10-year securities rising 64 basis points, a record in data going back to 1992. That was more than double the size of the move in conventional debt.

The BOE said it had consulted with the UK’s Debt Management Office. The DMO is set to sell £900m of index-linked bonds maturing 2051 on Tuesday.

The central bank also paused the sale of corporate bonds it accumulated during quantitative easing and confirmed that gilt purchase operations would only continue until Oct. 14.

“These additional operations will act as a further backstop to restore orderly market conditions by temporarily absorbing selling of index-linked gilts in excess of market intermediation capacity,” the BOE said.