Iran's parliament has banned Al-Jazeera television reporters from entering the group's building to protest perceived insults by the network against Iraq's most revered Shi'ite cleric, Iran's official news agency IRNA reported Sunday. The controversy started last week when the Egyptian host of an Al-Jazeera talk show, Ahmed Mansour, questioned Grand Ayatollah Ali al-Sistani's leadership credentials and whether he authored his own religious edicts. "The Majlis (parliament) has decided to ban reporters of the network from entering until it formally offers an apology over insulting Ayatollah Sistani," IRNA quoted the parliament speaker, Gholam Ali Haddad Adel, as saying. "We strongly support Shi'ite clerics, especially Ayatollah Sistani," he added. Iran's population is majority Shi'ite. Al-Sistani is an Iranian-born cleric who has been living in neighboring Iraq for decades and has emerged as one of the most influential figures in the country since the US-led invasion in 2003 because of his stature within the majority Shi'ite community. Following last week's show, hundreds of angry Shi'ites poured onto the streets of Basra and Najaf in Iraq to protest. Since the fall of Saddam Hussein's regime in 2003, Al-Jazeera has been seen by Shi'ite politicians as championing the former leader's rule and the Sunni insurgency. The 24-hour news channel, hosted by the Persian Gulf Arab state of Qatar, has been banned from operating in Iraq since 2004 and the latest controversy is likely to worsen its already tense relations with the Shi'ite-led government in Baghdad.