JERUSALEM, June 21 (Reuters) - Israel"s Defence Ministry and defence contractor Elbit Systems Ltd (ESLT.TA) are developing an airborne laser weapon to shoot down drones and other flying targets, officials said on Monday, predicting a prototype would be ready by 2025. They said the as-yet unnamed laser weapon could be incorporated in Israel"s multi-tier air defences, which include the Iron Dome system for downing short-range rockets and the David"s Sling and Arrow systems against ballistic missiles. Preliminary tests of the laser, flown on a light aircraft, were successful against several drones at ranges of around 1 km (half a mile) in recent days, Brigadier-General Yaniv Rotem of the ministry"s research and development section told reporters. "As far as we know we are the first one (country) - but maybe, for sure we are among the first countries - that have tried and succeeded (at) such an...interception," he said. Elbit makes C-Music, a defence system fitted to aircraft which uses a laser to "blind" incoming missiles. Oren Sabag, a senior Elbit official, said the new laser weapon would use tracking technologies similar to C-Music"s but would destroy targets by heating them up so they catch fire in "a few seconds". Rotem said a 100-kilowatt prototype with a range of 20 km (12.5 miles) would come out in three to four years. That suggested an operational version would take longer to roll out. The ministry, Elbit and state-owned Rafael Advanced Defense Systems Ltd are also working on a ground-based laser weapon for shooting down aerial threats. That would have a range of 8-10 km (5-6 miles) and be operational by 2025, the ministry said. The airborne version would have an advantage because it could be operated over clouds, eliminating bad-weather disruptions that can afflict ground-based lasers, Rotem said.