A SCOTTISH airport was last night at the centre of its second bomb scare in three days involving a passenger flight being escorted by RAF Tornados.

The Ministry of Defence said two Tornado F3s from RAF Leuchars in Fife were scrambled to escort an Aer Arann passenger flight into Prestwick airport in Ayrshire, after the pilot reported a suspected bomb on board.

The alarm was raised at 10.29pm when the Irish-based ATR 72 turbo-prop, which can carry 66 passengers, was en route from Luton to Galway in Ireland.

The plane was diverted to Prestwick under escort by two RAF jets and landed 26 minutes later.

Fifty-three passengers and crew members were taken from the plane, which was taken to the end of the runway, before being led into the terminal building where they were interviewed.

Last night, Strathclyde Police were planning to search the plane with explosive experts and sniffer dogs. Dozens of officers were involved in the operation.

Police could not say if anything suspicious had been found on the plane.

Earlier, an MoD spokesman said: "We had a civilian passenger aircraft with a suspected bomb on board. Two F3s were scrambled from Leuchars and the plane was escorted to Prestwick. Our involvement in the incident ended at 11.15pm and it has now been taken over by Strathclyde Police."

Strathclyde Police said in a statement: "At 10.29pm there was a report that a note was found claiming a bomb was on board the aircraft.

"The plane was diverted to Prestwick and is now on the ground having landed at 10.57pm. The passengers have been taken from the plane and are safely within the terminal building."

The incident comes just days after a Ryanair flight with 71 schoolchildren on board was escorted to Prestwick Airport by fighter jets.

In Wednesday's scare at the airport three Tornados were scrambled after a bomb alert was passed to the captain.

Passengers were left angry that they were forced to remain on the plane for more than two hours after it landed while a risk assessment was carried out.

Police later confirmed there were no bombs on board after all 167 passengers were questioned and a search of the aircraft found no suspicious objects.

Assistant Chief Constable John Neilson said the bomb alert was given to the captain in the form of a note in a magazine.

Ryanair said that flight FR25 had been diverted on the instruction of the Department of Transport, which is responsible for airport security.

According to Aer Arann's website it is Ireland's premier regional airline with a staff of 350.

The airline had a turnover of GBP65m and passenger numbers of just under one million in 2004, and is claimed to be one of the fastest growing regional airlines in Europe.

AerArann was established in the 1970s when it began flying from Galway to Aran Islands. Today the airline operates over 500 flights a week, including flights to Edinburgh, Glasgow, London and Manchester.