MAPUTO (Reuters) -Mozambique opposition leader Venancio Mondlane returned from self-exile on Thursday, defiantly claiming to have won a hotly contested October election, but security forces later used tear gas to disperse supporters who had gathered to greet him. “I’m here to prove that I didn’t leave Mozambique out of fear,” he said, ending a period of exile that began a few days after the vote, when Mondlane had said his life was in danger. The official winner of the presidential vote, Daniel Chapo, is to be sworn in next week, another potential flashpoint in Mozambique’s political crisis.