Palmyra amphitheatre
A picture taken on 14 March 2014 shows a Syrian policeman patrolling the amphitheatre in Palmyra, before it was taken over by Isis JOSEPH EID/AFP/Getty Images

The Islamic State (Isis) has executed three detainees by tying them to pillars and blowing them up in the ancient Syrian city of Palmyra. No details have emerged either about the identity of the victims or the nature of their crimes.

The three people were reportedly arrested by the terror group from Palmyra and its outskirts and murdered on Sunday (25 October). The IS "tied three individuals it had arrested from Palmyra and its outskirts to the columns...and executed them by blowing up" three columns, the head of the Syrian Observatory for Human Rights (SOHR), Rami Abdel Rahman was quoted as saying by The Independent. There are no reports of any propaganda videos of the executions being released so far. The killings were apparently carried out in the absence of a crowd.

Even local residents are in the dark about the identity of those killed, Khaled al-Homsi, a local activist from Palmyra city, said. "There was no one there to see (the execution). The columns were destroyed and Isis has prevented anyone from heading to the site." In recent days, the terror group has used various methods to kill: it ran a tank over a young Syrian soldier and forced people to dig their own graves with their bare hands.

After taking control of the Unesco World Heritage site of Palmyra in May, the IS has destroyed important historical places calling them "manifestations of polytheism". Besides, following Russia's announcement that it had bombed 285 terrorist targets in Syria, a video was released, showing IS fighters blowing up the 2,000-year-old iconic Arch of Triumph. IS has also destroyed the city's most important ruins, Temple of Bel and Baalshamin Temple, and used the city's amphitheatre for mass executions.