Satellite images showed a rise in the number of military support aircraft including refuelling tankers at a Saudi airbase used by the U.S. military during a four-day period in February, as Washington built forces in the region amid tensions with Iran. Saudi Arabia, a longstanding U.S. ally, told Iran last month it would not allow its airspace or territory to be used for military actions against Tehran, which held indirect negotiations with Washington on Thursday over its nuclear programme. In a high-resolution satellite image taken on February 21, at least 43 aircraft were visible at Saudi Arabia's Prince Sultan Airbase — which has hosted U.S. forces for decades — compared with 27 aircraft visible in a February 17 image. The number dropped to 38 in a February 25 image. Planes include Boeing KC-135 Stratotankers The aircraft in the February 21 image included 13 Boeing KC-135 Stratotankers and six Boeing E-3 Sentry aircraft known as AWACS, among a total of 29 large, swept-wing aircraft parked at the base, William Goodhind, a forensic imagery analyst with Contested Ground, told Reuters. I