By Karolina Tagaris PIRAEUS, Greece (Reuters) - They cheered, waved and flashed the victory sign when their boat, packed with thousands of mainly Afghan, Syrian and Iraqi refugees, docked at Greece's main port of Piraeus on Friday. As the stream of arrivals from Turkey across to Greece's islands continued unabated, nearly 4,000 people were ferried from the eastern islands of Lesbos and Chios to the mainland on Friday morning on two government-chartered ships. "(It will continue) as long as the war continues," Greece's new migration minister, Yannis Mouzalas, said after being sworn in on Friday.