Greece said on Monday it had prevented around 600 migrants from crossing the Aegean Sea into its territorial waters from neighbouring Turkey, in the largest attempted entry this year. A spokesman for the Greek coastguard said five sail boats and four dinghies had set off from the Turkish coast early in the morning. “Greek patrol vessels were able to quickly locate the vessels and inform the Turkish coastguard,” the spokesman told AFP. A coastguard statement said its boats had used “visual and sound signals” to keep the asylum seekers out of Greek territorial waters. All the vessels either head…