The trains on the Delhi Metro's Airport Express Line are being operated at a restricted speed between Dhaula Kuan and Shivaji Stadium stations due to the damaged signalling cables after a theft attempt, officials said on Sunday. About 800 metres of signalling cables were cut during the attempt in the midsection between the two stations, disrupting the signalling system, the Delhi Metro Rail Corporation (DMRC) said. The cut cable pieces were later found lying near metro pillar number 09 during inspection, it added. As a result, trains are being operated at a restricted speed of 25 kmph on the affected up line section towards New Delhi between Dhaula Kuan and Shivaji Stadium stations, DMRC said. Services on the remaining stretch of the Airport Express Line are running normally, it said. The Airport Express Line normally operates with a frequency of one train every 10 minutes, DMRC said, adding that replacing the damaged signalling cables during revenue hours is not possible without