Turkish forces swept into Syria overnight to rescue about 40 soldiers who had been surrounded for months by Islamic State militants while guarding the tomb of a revered Turkish figure, Reuters reports.

The Syrian government described the operation as an act of "flagrant aggression" and said it would hold Ankara responsible for its repercussions.

The action, which involved tanks, drones and reconnaissance planes as well as several hundred ground troops, was the first incursion by Turkish troops into Syria since the start of the civil war there nearly four years ago.

The military said no clashes took place during the operation although one soldier had been killed in an accident.

The 38 soldiers who had been guarding the tomb of Suleyman Shah, grandfather of the founder of the Ottoman Empire, were brought safely home.

Normally, the detachment is rotated every six months but the last one was trapped for eight months by Islamic State fighters.

The tomb, on a site within Syria that Ankara considers sovereign territory as agreed in a 1921 treaty, was to be relocated close to the Turkish border, while Suleyman Shah's remains were taken to Turkey.

"The remains of Suleyman Shah, along with ancestral relics, have been brought back to our country pending their temporary transfer to a new site in Syria," said Prime Minister Ahmet Davutoglu.

He told a news conference that nearly 600 soldiers, including special forces commandos, took part in the mission. Turkey had not sought permission or assistance but had informed allies in the coalition against Islamic State once it began.

"This was an extremely successful operation with no loss to our rights under international law," Davutoglu said, flanked by the chief of the military and the defense minister.

The Syrian government said in a statement that Turkey would be held responsible for its breach of the treaty after failing to wait for an agreement from Damascus before proceeding.

The Turkish government had informed the Syrian consulate in Istanbul about the operation but had not awaited Syria's agreement, a violation of the 1921 accord, it said.

"There will be a letter from the foreign ministry to the relevant parties in the Security Council," Syrian Tourism Minister Bisher Yazagi told Reuters.

A Turkish security source said the operation was conducted via the Syrian Kurdish border town of Kobani with the support of local Kurdish authorities. Kurdish forces, backed by U.S.-led air strikes, drove Islamic State from Kobani last month.