DONETSK, June 27 - 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, Reuters reported.

Pro-Russian separatists had detained eight observers from the Vienna-based Organization 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.