Rebels in southeast Ukraine early on Friday released four out of eight international observers, captured over a month ago, in an apparent goodwill gesture that could help pave the way to a resolution of the conflict that has so far claimed hundreds of lives. Pro-Russian separatists had detained eight observers from the Vienna-based Organisation for the Security and Cooperation in Europe (OSCE), a key security and rights body, tasked with monitoring an agreement drafted in Switzerland in April to de-escalate the crisis that has pitted the rebels against leaders in Kiev. Four observers from Switzerland, Turkey, Estonia and Denmark, part of the 100-strong mission, were brought by heavily armed rebels to a hotel in downtown Donetsk, where they were handed over to their colleagues. "It was a long road and this release is the fruit of good will and it was unconditional," Alexander Borodai, prime minister of the self-styled Donetsk People's Republic, told reporters.