Turkey says it has shot down Syrian warplane

ISTANBUL—Turkey said it downed a Syrian warplane on Sunday in Ankara’s first assault against the Damascus regime’s fighter jets, marking an escalation of tensions along the 565-mile border that serves as the main line of support for rebel fighters trying to oust President Bashar al-Assad.

“A Syrian plane breached our borders, our airspace; our F-16s took off and hit that plane,” Turkey’s Prime Minister Recep Tayyip Erdogan told thousands of flag-waving supporters at an election rally in the northwestern province of Kocaeli. Congratulating the armed forces, the premier also fired a salvo to Syria: “If you breach my airspace, our slap will be heavy handed going forward.”

Mr. Erdogan said the Syrian jet breached Turkey’s airspace at around 12:15 local time (10:15 GMT).

Syria condemned the “unprecedented and completely unjustified military aggression by the Turkish government” but didn’t say a Syrian military jet was downed, the official SAN’A news agency reported, citing a Foreign Ministry official that it didn’t identify.

The Turkish attack against Syria is the latest in a series of increasingly antagonistic interactions between the neighboring countries’ militaries. The General Staff in Ankara—which presides over the country’s armed forces—Sunday accused Mr. Assad’s military of harassing its jets by locking missile radars on Turkish warplanes for 20 seconds as they conducted border patrols on Saturday. In September, Turkish F-16 warplanes brought down a Syrian helicopter along the border.

Turkey’s armed forces declined to comment on the downing of the Syrian jet on Sunday. Analysts said Ankara hit the Syrian jet as per engagement rules revised in 2012, when Mr. Assad’s commanders downed a Turkish jet, claiming a breach of airspace. Turkey has maintained its reconnaissance plane was hit in international airspace.

Mr. Erdogan has been calling for Mr. Assad’s ouster since August 2011, when Ankara’s efforts to mediate a political solution to Syria’s brewing civil unrest failed. Syria accused Turkish military tanks and artillery of shelling its territory on Friday and Saturday “to provide cover for the entry of armed terrorist gangs from Turkish land into Syria,” according to SAN’A.

The Syrian jet crashed just west of Kassab after 1 p.m. local time, said Mehmet Celalettin Lekesiz, governor of Turkey’s Hatay province on the border. Islamist rebel factions near Kassab, including the al Qaeda linked Nusra Front, have been launching attacks on Syrian government forces since Friday as part of a new offensive on the country’s west coast, the Syrian official told SAN’A.

Turkey, home to more than 1 million Syrian refuges, denies assisting rebel forces.