Less than a year after declaring he had left Iraqi politics, the unpredictable Shiite cleric Muqtada al-Sadr has reminded his rivals of the influence he still wields after his supporters stormed and torched the Swedish Embassy in Baghdad.

Prompted by one man's plan to burn a Quran, the incident has dragged Baghdad into a diplomatic crisis and disrupted the relative calm enjoyed by Prime Minister Mohammed Shia al-Sudani since he took office with the backing of Sadr's Shiite rivals.

While condemning the storming of the embassy, in which nobody was hurt, the Iraqi government also moved to sever ties with Sweden over the threat to burn the Quran — after Sadr challenged it to take "a firm position."