ANKARA - The wife and a DNA-confirmed child of killed leader of Islamic State (IS) Abu Bakr al-Baghdadi have been held by Turkey, Turkish President Recep Tayyip Erdogan revealed on Thursday.

"His wife has been at our hands for the past 1.5 years. It's a sensitive issue for us that his DNA-confirmed child is also with Baghdadi's wife," the Turkish president told reporters.

The total number of Baghdadi's relatives that Turkey has captured is almost "in double-digit numbers", but Ankara does not want to announce them all at the moment, Erdogan said.

"I do not find it right to declare these right now. We will make a statement after everything gets clear," he said, citing that the investigation is still ongoing.

Turkey captured al-Baghdadi's sister and her husband in Syria on Monday, Turkish officials announced.

Al-Baghdadi was killed in a late night US-led raid on a compound near the village of Barisha in northwestern Syria on Oct 26.

Elaborating on Turkey's military operation into northern Syria, Erdogan said there were still members of Syrian Kurdish fighters in the safe zone and continued attacking Turkey-backed Syrian National Army in the region.

Erdogan said he would meet US President Donald Trump on Nov 13 and discuss the violation of the Turkey-US deal that stipulates the withdrawal of the Kurdish fighters from the safe zone in Syria.