Ankara, March 24 (IANS): The Turkish army said Sunday that it warned the Syrian warplanes four times of border violation before an F-16 fighter jet shot one down, an official statement said.

When two Syrian MIG-23 warplanes approached, the Turkish air forces warned them four times that they have approached 10 sea miles to the Turkish border, Xinhua quoted a statement issued by the General Staff of the Turkish Armed Forces as saying.

One of the aircrafts moved away before entering the Turkish airspace, while the other violated some one kilometre into the Turkish border near Yayladagi town of southern Hatay province.

An F-16 fighter jet, which was on duty in the region, fired against the Syrian MIG-23 warplane due to rules of engagement, the statement said, adding that the Syrian military plane crashed 1,200 meters inside the Syrian border.

However, Damascus slammed Turkey for shooting down its warplane "in the Syrian territory", saying it reflected Turkey's involvement in supporting the armed terrorist groups in the war- torn country.

Meanwhile, Turkish Prime Minister Recep Tayyip Erdogan warned Syria of "heavy" response if Turkey's airspace was violated.

"I congratulate our air forces, our pilots. From now on, our slap will be heavy," Erdogan said at a rally in Turkey's western province of Kocaeli.

Turkish President Abdullah Gul underlined that Turkey had demonstrated its determination to protect its borders.

In September last year, a Turkish fighter jet shot down a Syrian military helicopter after it allegedly entered Turkish airspace.