Mortar Bombs Found In Van In Londonderry Sky's Ireland correspondent David Blevins said: "It would appear that police have managed to thwart yet another attempted attack by dissident Republicans. "A huge security operation has been under way for several hours now but in the last few minutes Sky sources have confirmed to us that police intercepted at least three mortars last night. "One hundred families have been evacuated from their homes and we understand that two men, aged 35 and 37, have been detained. "We are being told by local people in the Letterkenny Road area that police stopped the van and there is some suggestion they stopped a motorbike at the same time before they took the two people into custody. "The police realised very quickly that they had intercepted the mortars primed for an attack in the vehicle with a Southern Irish registration number plate. "They have called in the Army bomb squad to defuse the devices." Blevins added: "The timing of any attack would be significant given that we are just four days away from a Westminster by-election in Northern Ireland in the mid-Ulster constituency - the seat which was formerly held by Sinn Fein's Martin McGuinness. "That indeed may have been why a possible attack was being planned by those opposed to the peace settlement."