Police in the Turkish capital of Ankara say that they have detained four Daesh members suspected of preparing an attack during May 1 International Labor Day demonstrations.

Turkish security officials told a correspondent of the state-run Anadolu Agency (AA) that the Ankara anti-terror department detained the four suspects at midnight on Saturday.

Saturday's arrests followed technical and physical surveillance and it is reported that the suspects are from Syria. The anti-terror operations will continue, say police.

The city saw its first mass meeting since October 10, 2015, when two Daesh suicide bombers attacked a peace rally organized by left-wing and pro-Kurdish political parties and trade unions, killing 103 people and injuring hundreds in Turkey's deadliest terror attack. Ankara was also targeted by PKK terrorists on February 17 and March 13 by car bombing attacks, killing 29 officers and civilian employees of Turkish Armed Forces and 37 civilians, respectively.

May 1 is celebrated by many labor unions and workers worldwide. May Day is generally a public holiday in many countries and is an official holiday in Turkey.