ANTI-TERRORIST detectives were last night investigating a wave of bomb hoaxes that brought panic to town centres across the country.

In the North-East and North Yorkshire, bomb disposal experts were called to deal with suspect packages at eight locations.

Nationwide, more than 30 hoax letter bombs were received.

All of them were sent to branches of the Children and Family Court Advisory and Support Service (Cafcass), the court service that handles child custody disputes.

Buildings were evacuated and roads closed as bomb disposal experts took no chances.

At some locations, children visiting estranged parents left in tears - terrified that a bomb was about to go off.

In Middlesbrough, staff at offices in Prudential House, Albert Road, had to be evacuated, along with 16 people waiting to sit driving theory tests on another floor in the building. The tests were resumed later in the day.

The organisation's Durham branch in Old Elvet and its regional headquarters in the city's Saddler Street were also evacuated at about 9am and the roads cordoned off.

The Saddler Street office had yet to open its mail when it was cordoned off. Police found a similar package among the post.

Hayley Green, regional business manager at the Durham headquarters, said: "We got back into the office at about lunch-time once the bomb squad had given us the all clear.

"We had no idea when we came in this morning that we had received a suspect package. But before we got round to looking at the mail, we had a phone call from other offices."

Other offices that received a suspect package included South Tyneside, Benton in Newcastle, Harrogate, York and Scarborough.

A spokesman for Scotland Yard said last night that its terrorist branch was co-ordinating investigations in conjunction with local police.

Bomb disposal experts from Catterick Garrison dealt with the incidents in Durham and Middlesbrough and took the packages away for analysis, but there was no need for controlled explosions.

The packages are said to have contained a substance that looked like thinly-rolled modelling clay.

Offices that escaped yesterday will be awaiting today's post with trepidation. Some key "at risk" locations in London will have a police presence.

Catherine Dow, from Cafcass's headquarters, said: "People have been led to believe they were opening explosive material and staff were so concerned they were evacuated from their buildings.

"Families with children use our offices as part of the work we do and there have been children caught up in all of this. It's an unpleasant experience for everyone."

She added: "We don't know who is sending them or why. There has been no communication with us about this. We weren't advised it was going to happen.

"There are people who have grievances about how our family court system works, but we have no experience of dealing with anything like this. It has never happened before."

Northumbria Police said it appeared the packages had been sent from London.

Cafcass steps in when there is a dispute between parents over custody of a child by making an application for the case to be heard at court.

Earlier this year, an organisation called Fathers For Justice daubed the doors of several offices in the South-West and East of England with graffiti.

Police said there was no link between the earlier action and the bomb hoaxes