Hezbollah Secretary-General Hassan Nasrallah is tightening security procedures for fear that Islamic State and the al-Qaida-affiliated group Nusra Front will try to assassinate him, the London-based pan-Arab daily Al-Quds Al-Arabi reported on Tuesday.

The Hezbollah chief is reportedly concerned that the radical Sunni Islamist rivals would seek to punish him for aiding forces loyal to Syrian President Bashar Assad in the five-year civil war.

According to the report, Nasrallah has solicited the services of the Iranian Revolutionary Guards, which has supplied the training for the Hezbollah leader’s personal bodyguards.

Nasrallah is reportedly holed up in a network of tunnels dug underground in south Beirut. In accordance with the new measures, only six guards have access to the Hezbollah chief.

The report also claims that Nasrallah has his food delivered to him from Tehran, allegedly for fear of poisoning.