In the midst of a heated war of words between Russia and Turkey after the latter shot down a Russian fighter plane along its border with Syria on Tuesday, one of the bigger worries in the Middle Eastern country is the expected heavy losses to its tourism. 

Russian foreign minister Sergei Lavrov on Tuesday advised citizens to not visit Turkey citing a threat of terrorism, after he cancelled his own visit scheduled for Wednesday following the shooting down of the Russian plane. 

However, Turkish media reported that local tour operators are among the most worried, fearing that they will lose out on millions of Russian visitors, who are reported to contribute $4 billion in revenue every year.

Russians make the second-largest market for Turkish tourism after Germans, with the resort city of Antalya considered one of the favourite destinations, as per reports.

3.3 million Russian tourists had visited Turkey in 2014, according to Hurriyet Daily News, while Today's Zaman put the figure at 4.48 million.

While the reports claimed that Russian visits dropped this year due to Russia's economic downfall and violence in the region, tourism had picked up after Russia cancelled flights to Egypt after the downing of the passenger plane in Sinai Peninsula last month that killed 224 people.

On Tuesday, Lavrov said that the the threat of terrorism in Turkey was no less than in Egypt.

Several Russian tour operators have cancelled tour packaged to Turkey for the 'near future'.

Turkish F-16 jets shot down a Russian Su-24 fighter jet after it reportedly violated Turkey's airspace. The plane crashed on the Syrian side of the border, and one pilot died after he was allegedly shot by Syrian rebels.

The incident led to an escalation of tensions between Russia and NATO, of which Turkey is a member, with US President Barack Obama also defending the Turkish move.