THE financial cost of rebuilding the damaged offices in London's Docklands following the recent IRA bombing could be up to £100 million, according to the chief executive of the London Docklands Development Corporation, Mr Eric Sorensen.

London's second biggest business district after the Square Mile was always a prime target for bombers. Two years' ago a bomb was left under the main tower block, which houses the Daily Telegraph newspaper. That was defused on time.

But the area, which houses 2,400 businesses with 67,000 employees did not raise security to the levels seen in the Square Mile - the area where many of the main financial firms are clustered around the Bank of England - since the Bishopsgate bomb there in April 1993.

The area close to where the bomb went off, houses investment banks Morgan Stanley and Credit Suisse First Boston, as well as advertising agency Ogilvey and Mather, six national newspapers and several government departments. Midland Bank, British Telecom and Bell Cable Media all have computer installations in the area.

Canary Wharf itself was first developed by Canadian, Paul Reichman. He developed 70 acres in the late 1980s and built five million square feet of office space in seven buildings. However, he went bankrupt in the process and the area took years to develop. Even now rents are far cheaper than in the West End or City.

At the same time 200 yards to the south across the dock, another complex called South Quay was erected. That is where the bomb went off.

South Quay cost £84 million to build. About 18 months ago Capital & Provident Management paid £7 million, on behalf of clients, for 360,000 square feet of the development.

There is a theory that the "ring of steel" around the City's Square Mile has made it practically impossible to detonate another large bomb in the area. Many access roads have been closed and vehicles are now monitored there. The towers at Canary Wharf also have tight security as access is restricted. "Canary Wharf itself is quite a difficult target," said Mr Sorensen. "But there was relatively free access to South Quay."

The corporation along with the police have tightened up considerably on security in the wake of the bomb. Police checks on individuals and cars have been put in place. New camera systems are also set to be introduced, according to Mr Sorensen.

These checks, as well, increased bomb scares as people become more vigilant, have slowed up traffic dramatically. In addition, the Docklands Light Railway, which runs through the area, is now stopping at Canary Wharf. A bus has been introduced to go further south.

As a result daily life is still in turmoil for many workers and businesses in the area and indeed across much of central London. Travelling to London from Dublin is also more difficult. Police with semi automatic weapons have been reintroduced at the airports and passengers should be prepared to establish their identity.

A spokesman for the Metropolitan Police at Heathrow Airport said security had been increased with more stop and search operations being conducted as well as additional armed police on duty. "We certainly have a more visible and increased presence," he said.

At the bomb site on South Quay many offices are still too dangerous to enter. Within the police cordons teams of loss adjustors and surveyors work with caution.

The Builder Group, which publishes titles such as Property Week and Building Journal was almost at the centre of the blast. Seventeen editorial staff were still at the premises when the bomb exploded. Most suffered minor injuries from flying glass and one lost an eye.

Kildare born Mr Gary McMahon, group librarian at the Builder Group, was on an underground train when the bomb exploded.

"I was sitting on the tube when the driver came over the tannoy and said `The IRA ceasefire is over. There has been a bomb at Canary Wharf, expect considerable delays.'"

"Our building is an adjunct of the Midland Bank building which took the force of the blast," said Mr McMahon.

"We haven't been allowed back in yet by the engineers. But from what we've heard we no longer have any archives or anything much else for that matter."

The group has now found offices just down the road at Marsh Wall. But staff are concerned about the risk of further bombs.

But apart from the debris which still surrounds the area, the Irish workers are very aware of their accents. "My editor rang me to say I shouldn't feel any blame or shame", said Mr McMahon. "But I wouldn't be too loud in a local bar here or indeed anywhere in London at the moment."

Mary O'Malley, a Cork born secretary from the group and Ms Deirdre Pearson from Carlow had also managed to leave the building before the explosion. "There's a joke that all the Irish were in the pub by 5.30 on a Friday," said Mr McMahon. "And thank God we were."

Staff at the Independent newspaper which is on the 18th floor of the main tower block just across the quay are also nervous of working in the area.

Mr Patrick Hosking, city editor of the Independent on Sunday, said he thought at first the explosion may have been gas. "We didn't know then about the breakdown of the ceasefire. There was an almighty bang and everybody dived under the table. We all expect a lot more bomb threats in the future. It's going to make it much more difficult to get about," he said.

Other businesses which were severely damaged include Bell Cable Media, the third largest cable TV and telecommunications company in Britain. The technical centre has been pronounced structurally unsound. However, within three hours of the explosion a full service had been resumed.

The Guardian printworks was less fortunate. Mr Nick Passmore, the Guardian's production editor, said the damage and disruption mean only the vaguest of guesses can be made about when the paper could be rolling off those presses again.

"The building is still standing but the force of the blast brought down power cables as thick as a man's wrist and ducting you could have crawled along.

"Suspended ceilings were sucked down in offices and plant rooms, bringing with them lights and air conditioning conduits. Soggy reels of newsprint, weighing a ton each even when dry, are swelling and bursting, threatening to topple the reels above them into the river of water and ink snaking across the floor."

Although most businesses insist they will remain in Docklands, some workers are less happy. "The problem is its all glass structures," said Ms Dido Sandler, a journalist on the Independent. "That makes us all feel a bit nervous.

In any case the explosion is almost certain to make the 2.8 million square feet of empty property in the area harder to let. Before the explosion rents were around £6 per square foot with an extended rent free period often thrown in, compared with more than £30 a square foot in the City and West End. Many expect that to fall further.