'Take up arms', Iraqi Shia told
Take up arms against insurgents, senior Shia Muslim cleric urges Iraqis as more towns fall
More to follow.
BBC News - Iraq conflict: Sistani issues Shia call to arms against militants
Iraq's most senior Shia cleric has issued a call to arms as Sunni-led insurgents sweep across towns.
The call by a representative of Grand Ayatollah Ali al-Sistani came during Friday prayers, as the militants widened their grip in the north and east and threatened to march south.
The UN says hundreds have been killed - with militants carrying out summary executions of civilians in Mosul.
The US and Iran have promised to help the fight against the insurgency.