The Turkish foreign ministry on Wednesday summoned the Greek ambassador in Ankara over "violations" of Turkey's waters and to warn Greece about its border units, a Turkish diplomatic source said. Athens' envoy Michael-Christos Diamessis was summoned to the ministry in Ankara, the source who did not wished to be named said. The ministry demanded "violations of Turkish territorial waters stopped and that Greece warned its units on the land border," the source told AFP, confirming an earlier report by state news agency Anadolu. Turkish officials also sought an end to journalists being detained on the islands of Rhodes and Lesbos "where they were reporting on asylum-seekers' humanitarian situation," the source said, without giving additional information. The Greek coastguard said earlier on Wednesday that one of its patrol boats was rammed by a Turkish coastguard vessel, although only minor damage was caused. Relations are tense between Greece and Turkey after Turkish President Recep Tayyip Erdogan in late February ordered the borders to be re-opened for refugees to leave Turkey. Thousands then massed at the land border with Greece this month where Greek authorities tear-gassed people trying to enter the country, and allegedly beat and stripped migrants of their belongings if they made it across the frontier. Erdogan raised the temperature earlier on Wednesday, insisting there was "no difference between what the Nazis did and those images from the Greek border." Greece has denied using violence and accused Turkey of pushing desperate people into dangerous attempts to enter Europe. raz/har