THE world was holding its breath last night as a virus threatened to wreak havoc with hundreds of thousands of computers.

An electronic "worm" was programmed to attack an estimated 300,000 computers worldwide without anti-virus or firewall software. It was due to strike at midnight in each country.

Internet users and computers with some Microsoft software packages had already been hit since the virus - described by experts as one of the most serious they have ever dealt with - was first detected on Monday.

In the North-East, big businesses and public sector organisations were confident they would not be hit.

Councils, emergency services, utility companies and health trusts have taken action to stop the Blaster worm causing mayhem in their organisations.

Some of Durham County Council's desk-top PCs crashed yesterday, but it is not known if the Blaster virus was to blame. None of the authority's databases was affected.

A spokeswoman said last night: "It was a minor interruption of administrative work. None of the frontline services were affected."

Computer experts at Middlesbrough and Darlington councils have detected the virus but have stopped it attacking their IT systems.

Northumbrian Water, npower, and British Energy, which operates Hartlepool nuclear power station, recorded a clean bill of health.

Cleveland Police said: "We have firewalls and various virus protection systems. We also have staff on-call 24 hours a day."

A spokeswoman for the Tees and Hartlepool NHS Trust said: "We have updated all our anti-virus packages and sent warnings to all our staff."

The Blaster worm is already affecting ntl, one of the most popular internet service providers in the region, and users of the Windows NT 4, 2000, XP and Windows Server 2003 operating systems.