Inmates knotted sheets to escape 17th-storey cell

A nationwide manhunt was under way in the US yesterday for two cellmates who broke out of a high-rise federal jail in Chicago by abseiling down its façade from 17 storeys above street level using torn strips of bed sheet they had tied together.

The FBI last night offered a $50,000 reward for any information leading to the apprehension of the two men, 37-year-old Joseph Banks and 38-year-old Kenneth Conley, warning that they both should be considered armed and dangerous. A raid on a house in southern Chicago proved fruitless. Banks, nicknamed the "Second Hand Bandit" was convicted last week of stealing more than $600,000 during armed robberies and Conley was convicted of stealing $4,000 last year from a bank in Homewood.

They may have been on the run for as long as nine hours before guards found that their beds in the lock-up were empty early on Tuesday morning. They had bunched up clothes under the sheets to look like bodies and apparently escaped through a window that was reported to be only 6in wide. Workers claimed to have seen the bed-sheet rope dangling from a 17th storey window when they turned up for work on Tuesday.

It has been almost 20 years since the last break-out from the fortress-like Metropolitan Correctional Centre in Chicago which is 27 floors high and has slit windows only a slim man could hope to fit through. On that occasion, two inmates similarly scaled down its outside walls but only from six floors up. "We're pursuing whatever leads develop," said Joan Hyde, an FBI spokeswoman.

"While some of those are out of state, our focus remains primarily in this area. Our focus is just to locate these guys and to get them back behind bars."

Prison escape carries a maximum penalty of five years in jail and a $250,000 fine, authorities explained in a statement yesterday.