Tighter airport security is set to be introduced by the end of the year with every bag going into a plane's hold being passed through an X-ray machine.

The contract is up for tender along with individual passenger screening.

Aviation Security Officer Roger Brydon said the system had been requested by UK authorities even before the September 11 terrorist attacks in the US, which led to security being tightened up worldwide.

He said British Airways had been screening hold baggage for some years but now a similar system would be brought in for the whole airport.

He said people were being more sensible with what they took on planes.

"On occasion we do get the odd passenger who tries to take on a small penknife."

Mr. Brydon explained razors and knives could be stored in bags in the belly of the plane but could not be brought on with carry-on luggage.

The airport is also planning to introduce electronic baggage monitoring which will make it easier to make sure extra bags are not put on the plane.

It will also help locate bags for passengers who have to come off the plane at the last minute.