Kurdish militants in northern Syria have fired rockets across the border into southern Turkey, killing two people and wounding 19. The attack followed Turkey's airstrikes over the weekend targeting Kurdish bases in Syria and Iraq.

The Kurdish rockets and mortar shells hit houses and a school in the Turkish border town of Karkamis on Monday, prompting Turkey to respond with artillery fire.

The Turkish government announced on Monday that its airstrikes were a retaliation for a deadly bomb attack on a bustling street in Istanbul a week earlier.

Ankara is blaming the Kurdistan Workers' Party, or PKK, for the bombing, which killed six people and wounded 81 others. The PKK is listed as a terrorist organization by Turkey and Western nations.

According to Turkey's media, President Recep Tayyip Erdogan says his country's operations will not be limited to an air campaign, and could involve ground forces.

The Syrian Democratic Forces, which is led by a Kurdish militant group and based in northern Syria, has vowed to accomplish its "historical mission" and continue fighting.