ISTANBUL - Four Turkish soldiers were killed and nine others wounded in an intense artillery shooting by Syrian forces in the northern Syrian region of Idlib, the Turkish defense ministry said Monday.

In immediate response, the Turkish fire support teams destroyed targets with intense shelling, according to a ministry statement.

One of the wounded is in critical condition, the statement noted.

"Developments are followed, and necessary measures are taken," it read.

The Syrian government forces, backed by Russia, have been carrying out airstrikes in Idlib, the last stronghold of rebels in the war-torn country, forcing civilians to leave their homes and move toward Turkey's border.

Turkish President Recep Tayyip Erdogan said on Friday that Turkey might consider launching a military operation if the bombardments in Idlib continue.