All Nimrod MR2 aircraft are being grounded due to fuel pump problems, Sky sources have learned. It comes after a dent was found in a fuel pipe on one of the planes two days ago. Checks are being carried out on about a dozen of the aircraft. The Ministry of Defence has stressed that there have been no fuel leaks. At this stage it is not being linked to the official inquiry into the Nimrod crash in Afghanistan last September. Fourteen servicemen lost their lives in the incident, amid reports that fire was seen on the fuselage before it came down. In a staement the MOD said: "As a precautionary measure the fleet was grounded while the issue was investigated. "These investigations are ongoing, but some of the aircraft have been cleared of this problem and we expect others to follow shortly. "This decision was taken as a precautionary measure and should not be construed as pre-judging the findings of the Board of Inquiry into the circumstances surrounding the loss of XV230."