Six people have been arrested, police said yesterday, after officers on Wednesday night freed 18 migrants who were locked up in cramped conditions and held to ransom in a warehouse in Aspropyrgos, west of Athens. The migrants were from Afghanistan and various African countries and had been brought into Greece illegally by human traffickers, officers said. Some of the victims said they were beaten by their captors. It was not clear how long they had been held for. Officers were tipped off by relatives of the victims who told police that the traffickers had demanded 3,000 euros for the release of each migrant. After inquiries, police found the warehouse and raided the building, arresting three suspects in the process. The other three alleged traffickers were arrested after a sting operation. The migrants said they had arrived in Greece in a boat which docked at a remote beach, but it was not clear exactly where this happened.