The Greek coastguard stopped about 600 migrants from reaching its territorial waters in the largest attempted crossing of the Aegean Sea from Turkey this year. The country’s coastguard said it had used “visual and sound signals” to keep the nine boats out its waters. All of the boats headed back towards Turkey or were intercepted by the Turkish coastguard, a Greek official said on Monday. EU member Greece regularly blames Turkey for not taking sufficient action to curb people smugglers who send migrants in unsafe boats and dinghies from its shores, in breach of a 2016 agreement with the EU. <a href="https://www.thenationalnews.com/world/europe/2022/03/18/syrian-refugee-sues-eu-border-agency-frontex/" target="_blank">Rights groups</a> have accused Greek authorities of pushing back migrants out of its territorial waters, sometimes with the collusion of the European border agency, Frontex. Its former chief Fabrice Leggeri quit last month after a misconduct probe, which looked at mismanagement and allegations of<a href="https://www.thenationalnews.com/world/uk-news/2021/07/15/turned-away-frontex-complicit-in-illegal-pushback-of-asylum-seekers/" target="_blank"> illegal “pushbacks” </a>by Frontex vessels and subsequent cover-ups. EU Commissioner Ylva Johansson visited the agency’s headquarters in Warsaw, Poland, on Tuesday to meet senior staff after strongly criticising the previous Frontex leadership. She said <a href="https://www.thenationalnews.com/world/europe/eu-s-frontex-border-police-get-new-powers-on-migrant-deportation-1.1212616" target="_blank">the agency</a> must operate in full compliance with the law, according to the Politico website, citing officials. Greece has always denied that its security forces engage in illegal pushbacks. It says migration flows to the Greek islands in the first four months of 2022 were about 30 per cent higher than in the same period last year. Government figures show that more than 3,000 asylum seekers have arrived in Greece so far this year, including more than 1,100 last month. There is also heightened migrant activity on Greece's land border with Turkey because water levels are low on the River Evros that divides the two countries.