NICOSIA — The tinny howl of air raid sirens echoed across ethnically divided Cyprus at the crack of dawn on Saturday, marking 50 years from the day that changed the island nation’s history.

It’s heard every year as the Greek Cypriot controlled south laments the date Turkish troops invaded in the wake of a coup by supporters of union with Greece.

In Cyprus’ northern third, Turkish Cypriots are celebrating what they see as salvation from the clutches of the Greek-speaking majority after years of armed conflict over the island’s fate.

It’s also a celebration of the establishment of their breakaway state, which is still recognized only by Turkey. The country still maintains more than 35,000 troops there.

Turkey’s President Tayyip Erdogan will preside over “golden jubilee” events, replete with a military parade, a visit by Turkey’s first aircraft carrier, and an airshow.

For Greek Cypriots in the south — where the internationally recognized government is seated — it’s the anniversary of a catastrophe that left thousands of people dead or missing and displaced a quarter of the Greek Cypriot population. Commemorations include the unveiling of memorials to fallen heroes, church services and a gathering at the Presidential Palace addressed — for the first time — by Greek Prime Minister Kyriakos Mitsotakis.

After numerous failed rounds of United Nations-brokered talks to reunify the island as a federation of Greek Cypriot and Turkish Cypriot zones, Cypriots on both sides still hold out a glimmer of hope that some common ground can be found.

But that’s proving tough since the last serious push for peace collapsed seven years ago. After the talks ended, Turkey and the Turkish Cypriots called for for what essentially amounts to a two-state deal, a notion that’s dismissed out of hand by Greek Cypriots.

U.N. Secretary-General Antonio Guterres is now mulling whether to call for another round of talks. He will base his decision on a confidential report his personal envoy, Colombia’s Maria Angela Holguin Cuellar, drafted after spending six months scoping both sides out.

The European Union, which Cyprus joined in 2004, urged both sides to show “genuine commitment” to a peace deal in line with the U.N.-endorsed plan for a federated island.

“Too much time has been lost,” an EU spokesperson said. “A forced division can never be a solution. Hope for a better future, a united Cyprus, still exists.”