SUKKUR, Jan 23: Cracks have developed in the structure of Sukkur barrage, the largest system of irrigation in the world and the backbone of the country's agriculture.

The cracks have been caused by a ditch, at least 50-foot deep, occurring between gates No 2 and 3. Stone pitching has been under way for a few days to fill the ditch. Superintending Engineer Sukkur Barrage Arshad Ahmed Khawaja told Dawn that the ditch detected some four days back was 'natural' and 'occurs often'. However, he said, it posed no threat to the structure.

This correspondent saw more than 25 people engaged in pitching stones on Friday. The engineer incharge declined to comment on the cause of the damage.