HOLY CITY OF NAJAF, Iraq: As the safety of Al-Marje Al-A’ala Sayyed Ali Al-Husseini As-Sistani is in question after one of his close aides was stabbed to death, security at his compound has been stepped up with more armed guards posted at the entrance which lies off the city's storied Rasoul street close to the gold-domed shrine of Imam Ali (AS).

Holy Najaf's police chief, Brig. Gen. Abdul-Karim al-Mayahi, said authorities had arrested the alleged killer — a security guard at the compound of the much-revered cleric, Ayatullah As-Sistani.

According to an official at the Ayatullah's office said the person arrested may have only played a supporting role in the weekend killing of Sheik Abdullah Falak al-Basrawi. His death came a little over a month after another As-Sistani aide was killed in a drive-by shooting.

The official, who spoke on condition of anonymity because he was not authorized to speak to the media, said Sistani's office will launch an independent investigation into the killing of al-Basrawi, a confidante of Sistani who was in his late 30s.

Al-Basrawi ran an office that collected "khoms."

Ayatullah As-Sistani has been the target of at least one assassination attempt since 2003.