A Turkish jet intruded into Greek airspace, which according to the Turkish General Staff, led two Greek jets to keep a radar lock on it as a target.

Two Greek F-16 fighter jets held a radar lock on a Turkish F-16 over the Aegean Sea, the Turkish General Staff said on Thursday.

Turkey refuses to recognize a 10-mile airspace zone around Greek islands in the Aegean Sea, which led to 1,233 airspace violations so far this year, 31 of which took place over Greek territory. On November 24, Turkey shot down a Russian jet over Syria for an alleged airspace violation.

“The Turkish F-16 fighter jet was conducting a training flight over neutral waters. During its mission, two Greek air force F-16s began pursuing our fighter jet, holding it as a target on the radar for three minutes and 40 seconds,” the Turkish General Staff said in a statement.

The General Staff’s statement added that its pilots demonstrated “the necessary reaction.”

Turkey has a long history of intruding Greek airspace, with incidents rising over the past several years, to 1,269 in 2014. Intruding flights over Greek territory have more than doubled in 2015, compared to the previous year.