The cost of restoring the IT infrastructure damaged in last week's terrorist attacks has been put at $15.8bn (£10.8bn) by US research company Computer Economics.

The firm said the immediate cost of restoring services damaged in the attacks would be $1.7bn ($1.2bn), with a long-term impact of $8.1bn (£5.5bn) on end-user organisations.

The long-term impact on communi-cations infrastructure was put at $6bn (£4.1bn) by Computer Economics.

"It is likely that more than 100,000 information intensive workers will be relocated to temporary and new permanent facilities," a statement said.

These costs include acquiring and installing telecommunications and data communications support and replacing servers and computers.