Turkish F-16 fighter jets were scrambled after a Russian warplane violated Turkey’s air space on Saturday, the foreign ministry said.

Russia said the incident was a “navigational error” and it has “clarified” the matter to Ankara.

Turkish jets patrolling the border were also “harassed” by an unidentified plane on Sunday, Turkish military said.

Russia has been carrying out air strikes in Syria in support of President Bashar al-Assad.

Turkish Prime Minister Ahmet Davutoglu said “the rules of engagement are clear,” whoever violates its airspace, according to Turkish TV.

The Turkish foreign minister, Feridun Sinirlioglu, has spoken to his Russian counterpart Sergei Lavrov, as well as ministers from other Nato countries.

The Russian fighter plane “exited Turkish airspace into Syria” after being intercepted, the ministry said.

The Russian embassy in Ankara told the BBC that a Russian plane did violate Turkish airspace on Saturday.

Turkey’s military said they did not know the nationality of the plane which its jets patrolling the Syrian border encountered on Sunday.

The Russian air campaign began on Wednesday, with Moscow insisting it was targeting Islamic State (IS) positions. But Syrian activists say Russian planes have also targeted other Syrian groups opposed to President Assad. BBC