THE number of foreign visitors to Turkey fell by 28 percent in April, official data has revealed, – with the biggest drop since 1999.

The decline signals more pain for Turkey’s economy, which is smarting from slowing exports and weak private investment. Some economists have forecast that tourism revenue will drop by a quarter this year, costing around $8 billion, or the equivalent of 1 percent of GDP, reported Reuters.

The drop-off does not bode well as Turkey heads into the May-August high tourism season, when European holidaymakers usually flock to its southern beaches.

“As we move from low to high season in tourism, the deterioration in tourism statistics gets more and more significant,” said Deniz Cicek, an economist at Finansbank in a note to clients.

Tourism fell 28.07 percent year-on-year in April, with 1.75 million people arriving, data showed. It was the biggest drop since May in 1999.

The number of Russian visitors all but evaporated, falling by nearly 80 percent, the data showed. Russians traditionally account for one of the biggest groups of foreign visitors after Germany, but they have stopped coming after Turkey shot down a Russian warplane over Syria last year, souring relations.

The number of Germans fell by more than a third.

“The substantial decline in tourist arrivals this year was not limited to Russia, and spread out to all major tourism partners of Turkey to some extent,” Cicek said.

The pronounced drop in tourism is yet another headache for a government trying to win back investor confidence.