The head of Syria's National Security Bureau (NSB), which is the top intelligence body of the Assad regime, has been placed under house arrest due to suspicions that he was plotting a coup against President Bashar al-Assad. According to an article published by British daily The Telegraph, NSB's Ali Mamlouk, one of the few officials still to have access to Bashar al-Assad, was accused of holding secret talks with countries backing rebel groups and exiled members of the Syrian regime."Mamlouk had been communicating with Turkish intelligence through an intermediary," quoted The Telegraph a senior regime source with direct knowledge of the plan.It was also reported that Mamlouk was contacting Assad's uncle Rifaat al-Assad through an intermediary, who has been living in exile since 1980 since he was accused of seeking to mount a coup in Syria in the 1980s.Mamlouk reportedly began his efforts as a result of increasing losses by the regime, including the northern cities of Idlib and Jisr al-Shughour, to opposition forces, despite Iranian support.The article states that Assad is struggling to keep together the "inner circle" of his regime, which is showing divisions over the role of regional ally Iran, which has assumed more power since the beginning of the civil war in 2011."Most of the advisers at the presidential palace are now Iranian," said a source close to the palace. "Mamlouk hated that Syria was giving her sovereignty up to Iran. He thought there needed to be a change."Mamlouk and Rustum Ghazaleh, a prominent regime figure who died last month after being attacked by men loyal to General Rafiq Shehadeh, are both of Sunni Muslim origin.An opposition fighter quoted in the article highlighted the tension between Iranian fighters and local groups loyal to the Assad regime.