ISTANBUL: Two more Turkish troops were killed on Tuesday by an explosion while taking part in Ankara's unprecedented military operation inside Syria, state media said.

The state-run Anadolu news agency said the soldiers were killed by a mine north of the Syrian town of Jarabulus, which pro-Ankara militants had seized from the militant Islamic State (IS) in the early stage of the operation.

They were taken over the border to hospital in the southeastern Turkish city of Gaziantep but died of their injuries, it said.

The soldiers had been been helping to build a security wall aimed at firming Ankara's control of the border.

It was not clear who was behind the blast and how long ago the mine had been planted.

The latest deaths bring to 10 the number of Turkish soldiers killed since Turkey began its “Euphrates Shield” operation to secure the Syrian border area on August 24, the Dogan news agency said.

Most of them have been killed by IS but one was killed in an attack blamed on the People's Protection Units (YPG) Kurdish militia, which is also targeted in the offensive.

Turkey sees the YPG as a terror group affiliated with the outlawed Kurdistan Workers' Party (PKK) which is waging a bloody campaign against the Turkish state.

After seizing Jarabulus on the first day of the operation, the pro-Ankara Syrian militants backed by the Turkish tanks and air power are now preparing to go further south to IS-held Al-Bab.

Before leaving for the UN General Assembly in New York, President Recep Tayyip Erdogan said Monday that Turkey could create a 5,000-square-kilometre safe zone in Syria.

Meanwhile, the government has submitted to parliament a bill requesting a year-long extension of an existing mandate allowing it to send troops into Iraq and Syria, Anadolu said.

The mandate was first approved by parliament in October 2014 and was renewed for another year in September 2015. It allows military action in Turkey's two southern neighbours against IS and other militant groups.

The current mandate runs out on October 2. With the ruling party holding a comfortable majority and nationalists also supportive, the bill should pass easily when it comes to vote.