Cypriot police said the Turkish coastguard fired warning shots at one of its vessels patrolling for undocumented migrants off the island's north coast on Friday, as tensions mount ahead of a visit by the Turkish president to the breakaway north.
The Cyprus government said it was preparing a protest to the United Nations over the incident, which it said was the first of its kind.
But a Turkish diplomatic source denied that either the Turkish or the Turkish Cypriot coastguard had fired on any Greek Cypriot vessel.
Turkish President Recep Tayyip Erdogan is due in the breakaway north of the island next week to mark the anniversary of Turkey's 1974 invasion, a visit Greek Cypriots see as inflammatory with reunification talks in limbo.
The Cypriot police vessel spotted the Turkish coastguard some 11 nautical miles from the small fishing port of Kato Pyrgos, just west of the UN-patrolled armistice line separating government-held territory from the north, the Cyprus News Agency reported.
Cyprus police spokesman Christos Andreou told CNA that the coastguard cutter was inside Cypriot territorial waters at 3:30 am (0030 GMT) when the incident took place.
He said the boat was on a regular patrol to check for irregular migrants, as the area is a dropping-off point for migrants coming from Turkey.
- 'Aggressive behaviour' -
"The patrol boat's three-member crew, seeing the intentions of the Turkish coastguard, tried to avoid any incident and headed toward the fishing shelter at Kato Pyrgos," he said.
"At a distance of four nautical miles from the shelter, the marine police boat received warning shots from the Turkish coastguard.
"Then, being a short distance from the shores, the Turkish coastguard left for the occupied territories" (of northern Cyprus), he said.
Cyprus government spokesman Marios Pelekanos told public television the government was preparing a protest to the UN, even though the world body's peacekeeping mandate on the island does not extend offshore.
He said the patrol boat was acting within its rights inside Cyprus territorial waters, and the incident highlighted Turkey's recent "aggressive behaviour" towards the island.
"There has not been a previous incident of this nature," Pelekanos said.
The Turkish diplomatic source denied any coastguard vessel had opened fire.
"A Turkish or a Turkish Republic of Northern Cyprus vessel did not fire at a Greek Cypriot boat. It is not true," the source told AFP.
Tensions have been running high ahead of Erdogan's visit to the island, when he will make what Greek Cypriots see as a provocative tour on Tuesday of the abandoned beach resort of Varosha, which was emptied of its Greek Cypriot residents by the Turkish invasion.
UN-backed talks on reunifying the island as a bicommunal federation collapsed in 2017 and efforts to revive them have hit a new, tougher line from Ankara demanding a two-state solution.
- 'Difficult situation' -
Cyprus police have stepped up both land and sea patrols since the government declared a "state of emergency" in May, following an influx of Syrian migrants that has flooded its reception centres.
Nicosia says most migrants enter government-controlled areas illegally, via the UN-patrolled buffer zone from the north.
Cyprus, the European Union's most easterly member state, has had the bloc's highest proportion of asylum applications per capita for four consecutive years.
Nicosia has asked the EU for help preventing irregular migrant flows from Turkey before they reach Cyprus, equivalent to an arrangement for Greece agreed in 2016.
"Despite the enormous efforts by the Cypriot authorities to manage the disproportionate migratory pressures, we are still in an extremely difficult situation," Interior Minister Nicos Nouris told reporters in June.
He said the division of the island by a 180-kilometre-long (112 mile) ceasefire line "creates unique conditions for the development of irregular migration".
"Unfortunately, during the first months of 2021, the increasing irregular arrivals, especially of Syrian nationals, either by sea or land through the Green Line, indicate an alarming trend," he said.
"The continuation of the large numbers of migration flows from Turkey is the main challenge for Cyprus."
Giannis Ioannou, founder of think tank Geopolitical Cyprus, said the incident reflected "a Turkish approach to create a new de facto situation in order to further undermine the Republic of Cyprus".
"We need to see if this poses a hybrid threat regarding migration, since Kato Pyrgos is a destination for boats approaching Cyprus from Lebanon and Syria," Ioannou said.