Turkish police officers secure the area after a rocket hit a restaurant in Kilis province. -AFP

KILIS: Four people were injured on Thursday after rockets fired from Syria hit the Turkish border province of Kilis, the governor said.

Two rockets hit a restaurant and a house in the centre of Kilis on the 13th day of Turkey's offensive against the Kurdish YPG militia in the northern Syrian region of Afrin.

Four people were wounded, Kilis governor Mehmet Tekinarslan told reporters. The front of the restaurant was smashed, AFP correspondents said.

Security forces cordoned off the area and ambulances quickly arrived on the scene to evacuate the injured.

Shortly after the attack, Turkish artillery fire could be heard from the centre of Kilis.

Multiple rockets have hit the Turkish border provinces of Hatay and Kilis, killing at least five people.

Turkish media blames the rockets on the Kurdish People's Protection Units (YPG), viewed as "terrorists" by the Turkish government which wants to remove them from their enclave of Afrin.

Ankara says the YPG is an offshoot of the outlawed Kurdistan Workers´ Party (PKK) which has waged a three-decade insurgency against the Turkish state.

But the YPG has been working closely with the United States against the Islamic State group in Syria, capturing swathes of territory from the extremist organisation last year.