SIERRA Leonean rebels appear to have released the last of more than 500 UN peacekeepers they took hostage almost four weeks ago when a peace accord collapsed. “We are optimistic that the release of the hostages signals a positive change of direction by the Revolutionary United Front in coming back to seek a peaceful settlement,” said David Wimhurst, the UN’s spokesman in Freetown. The last group of 85 hostages — all Zambian apart from a Gambian observer with a broken leg — returned to Freetown from the Liberian capital Monrovia on Sunday night. Wimhurst discounted reports that 30 of the hostages had been wounded.