Large numbers of Shia volunteers are signing up to join security forces in Iraq, to take on Sunni rebel groups that have captured large areas north of Baghdad. It is giving the sectarian dimension to the ongoing turmoil an added edge.

Civilians are answering a call to arms from Prime Minister Nouri al-Maliki and Iraq's most senior Shia cleric, Grand Ayatollah Ali al-Sistani. It follows sweeping gains made by fighters from the al-Qaeda splinter group, the Islamic State of Iraq and the Levant, or ISIL, and other disaffected Sunnis.

Reporting from Baghdad, Al Jazeera’s Imran Khan said the Association of Muslim Scholars had argued that "Sunni rebels are allowed to march on Baghdad and effect regime change in this country because of Nouri al-Maliki’s sectarian policies."

Speaking in Washington DC on Friday, US President Barack Obama said: "Any action that we may take to provide assistance to Iraqi security forces has to be joined by a serious and sincere effort by Iraq's leaders to set aside sectarian differences."

So can the Iraqi prime minister, Nouri al-Maliki, unite a fractured nation? Or are his sectarian policies at the heart of the unrest?

Presenter Adrian Finighan

Guests: Lara Fatah - an Iraqi-Kurdish analyst.

Alaa Makki - an Iraqi member of parliament with the Wataniya Alliance.

Sabah al Mukhtar, president of the Arab Lawyers' Association, which has acted for the Iraqi government.

Source: Al Jazeera