Arab News Agency crediting its antiaircraft gunners with downing an unidentified aircraft flying at "very low altitude and at high speed" over Syria's territorial waters toward land less than a mile offshore, causing it to crash into the sea west of the village of Om al-Tuyour. Syrian Foreign Ministry spokesman Jihad Makdissi said "the downing was an accident, caused by the "automatic response" of an officer commanding an anti-aircraft gun. The man saw a jet coming at him at high speed and low altitude and opened fire, Makdissi said." The statement went on to claim that the aircraft was found to be a "Turkish military plane that entered Syrian airspace and was dealt with according to laws observed in such cases". The downing occurred at a time of heightened tensions between the two countries due to Turkish support for Syrian rebels opposed to the Bashar al-Assad regime in Damascus. On 24 June, wreckage of the F-4 was located in Syrian waters, but the crew had not been found. On 24 February 2015, two RF-4Es crashed in the Malatya region in southeast Turkey, under unknown circumstances, killing all four crew members. On 5 March 2015, an F-4E-2020 crashed in central Anatolia killing both crew. Calls to scrap the F-4s and replace them with the fifth generation F-35s were renewed. Upgrades Turkey considered more sophisticated supersonic fighters like the F-15 Eagle or Panavia Tornado to be too expensive; instead, the THK decided to upgrade its Phantom fleet with improvements to avionics and structure, but not to the engines. In August 1995, after a hotly contested competition with DASA (F-4 ICE), IAI was awarded a USD600M contract to upgrade 54 F-4Es to Phantom 2000s. The first 26 aircraft were rebuilt in Israel, and the other 28 in Turkey. Structure Small strakes above the air intakes to improve agility, new attachment fittings, engine mountings, stronger wing fold ribs, updated canopy sill bar, 12 mi (20 km) of wiring replaced (reducing weight by 1,653 lb/750 kg) as well as most hydraulic and pneumatic lines and hoses, and fuel tank reinforcements. Avionics New multifunction display in the front cockpit plus two in the rear, new Kaiser El-OP 976 wide-angle HUD and HOTAS system, high-performance Elta EL/M-2032 ISAR-capable high-resolution SAR/GMTI (ground moving target indicator) multi-mode fire-control radar (developed for the IAI Lavi), IAIC mission computer, new navigation equipment including GPS/INS connected to mapping mode, dual MIL-STD-553B databus