GUERNSEY air passengers are today being affected by a major UK anti-terror operation which disrupted a plot to blow up aircraft in mid-flight. Massively heightened security measures at all UK airports, including the Channel Islands, are creating widespread delays and confusion.

Shortly before 9am, airports operator BAA asked for all in-bound Heathrow flights not in the air to be suspended.

Security experts this morning said that although numerous arrests had been made in Britain, the terrorists were still intending to detonate devices on board passenger aircraft en route to the US.

MI5 has raised the threat level to critical – the highest possible and the first time that threshold has been applied.

Guernsey Airport was shocked at the news this morning but officials said that passengers seemed ready to respond.

Red-eye flights to the UK were slightly delayed, but huge knock-on hold-ups from the UK were expected for the rest of the day.

Alan Herpe, terminal duty officer, said: ‘Heightened security measures were put in place this morning because of the threat in England. Everything has run smoothly. Most of the flights have gone off on time.’

The security measures will carry on until further notice.

‘It’s all caught us on the hop this morning and the managers have come in early to deal with it.’

Passengers were given a list of items that they could take on board as hand luggage, but only in a clear plastic wallet. These included passports, keys, medicines, wallets, travel documents, baby food.

Passengers were told to put their hand luggage into their main bags for storage in the hold.

At about 7 this morning passengers were busy emptying hand luggage into their suitcases on the floor of the terminal.

Mr Herpe said the threat had to be taken seriously.

‘You cannot be confident of anything. I cannot say to you ”It is Guernsey, it won’t happen”. We are classed as a UK airport and have to follow UK guidelines.’

Michelle Holmes, 37, from Ashby-de-la-Zouche, was on her way to Birmingham.

‘It’s been quite calm really,’ she said. ‘It’s just a good job that there’s not lots more people here as it would have been horrible to have to do this on the floor of the airport with lots more people.’

Pam Pettinger was also flying to Birmingham but said she had been told that the airport there was closed, although she did not know why.

She was pleased that the security measures had been put in place in light of the threat.

‘I would sooner be safe than sorry. It’s been very relaxed but with a bit more security.’

Police officers were patrolling the airport this morning.

Barbara Parks, duty manager for Flybe, said she heard about the threats on the radio.

Flybe delayed opening its check-in by 15 minutes and there were 10-minute slot delays on the flights to Southampton and Gatwick. ‘It could have been hours with a major security alert but we have been lucky,’ she said.

There were similar scenes at Jersey Airport today with passengers describing security as ‘extremely tight’.

Business traveller John Varcoe, general manager of MSP publishing, said that passengers were being told to travel with no hand luggage, just travel documents and spectacles. Even his newspaper was confiscated.

Shoes were being screened and all passengers hand searched.

‘They are taking it extremely seriously at this end,’ he said.

The Guernsey cricket squad was stuck at Glasgow waiting to fly to Gatwick.

Captain Andy Biggins said the cricketers had been told that Heathrow was shut and were expecting long delays on their Gatwick flight, which was due to leave at 9.05am.

The team was considering switching to a flight from Edinburgh to Jersey to minimise inconvenience.

‘The mood here is OK – a bit subdued about what’s going on,’ he said.

‘I think we’re just going to have a long day at the airport.’

Aurigny managing director Malcolm Hart warned that there would be major disruption to services during the day but said it was vital for passengers to check in on time.

‘We’ll be doing whatever we can to minimise delays,’ he said.

Home Secretary John Reid confirmed that there had been a plan ‘to bring down a number of aircraft through mid-flight explosions, causing a considerable loss of life’.