Authorities Saturday released from custody 135 suspects who were rounded-up in relation to deadly clashes in a Shiite pilgrimage site in Karbala which killed 52 Iraqis last month. Reportedly, only 15 of the discharged were Sadrists, according to dpa. On August 28, Shiites engaged in a deadly gunbattle near two sacred shrines in Karbala during an annual Shiite festival as the holy city hosted over four million Shiite pilgrims. According to police sources and witness reports, Shiite cleric Moqtada al-Sadr's armed supporters - enraged at being held back from visiting the shrines for security reasons - started shooting at Shiite security forces, scaring the crowds of visitors. The incident was branded "the Karbala sedition" and Shiite clerics started accusing foreign forces and former Baath party supporters for causing the chaos that lead to the bloodbath. Al-Sadr called for an official probe into the incident after imposing a six-month freeze on his radical armed followers known as the Mahdi Army. But warned of "retaliation" if the investigation was not neutral or was unnecessarily delayed. When scores of Mahdi army affiliates were rounded-up in Karbala- related arrests later, Sadr's office decried "bias" and "injustice" and Sadr himself shot back with another "ultimatum."