IRAQ’S most senior Shia cleric last night issued a call to arms as Sunni militants seized more towns and the United Nations warned of “murder of all kinds” in the warzone.
Earlier claims that fighters from the Islamic State of Iraq and al-Sham (Isis) was allowing surrendering soldiers and civilians to walk free were quashed as harrowing footage emerged reportedly showing civilians being led away to be killed.
UN officials expressed “extreme alarm” at reprisal killings in the offensive, citing reports of hundreds of dead and wounded.
In one video, Isis fighters are seen knocking on the door of a police major at night, before seizing, blindfolding and decapitating him.
United States president Barack Obama last night said he is weighing options for countering the insurgency, but warned Iraqi leaders that he would not take military action unless they moved to address the country’s political troubles.
Fighters from the al-Qaeda-inspired Isis made fresh gains, capturing two towns in an ethnically mixed province northeast of Baghdad.
The Isis assault also threatens to embroil Iraq more deeply in a wider regional conflict, feeding off the chaos caused by the civil war in neighbouring Syria.
The fast-moving rebellion, which also draws support from former Saddam Hussein-era figures and other disaffected Sunnis, has emerged as the biggest threat to Iraq’s stability since the US withdrawal in December 2011.
It has pushed the nation closer to a precipice that could partition it into Sunni, Shiite and Kurdish zones.
Prime minister Nouri al-Maliki’s Shiite-led government is struggling to form a coherent response after militants overran the country’s second-largest city of Mosul, Saddam’s hometown of Tikrit and smaller communities, as well as military and police bases – often after meeting little resistance from state security forces.
A representative for Grand Ayatollah Ali al-Sistani, the most revered Shi’ite spiritual leader in Iraq, told worshippers at Friday prayers that it was their civic duty to confront the threat.
“Citizens who can carry weapons and fight the terrorists in defence of their country, its people and its holy sites, should volunteer and join the security forces,” said Sheik Abdul-Mahdi al-Karbalaie, a cleric whose comments are thought to reflect Ayatollah al-Sistani’s thinking.
He warned that Iraq faced “great danger” and that the responsibility of fighting the militants “is everybody’s responsibility, and is not limited to one specific sect or group”.
In Geneva, UN human rights chief Navi Pillay warned of “murder of all kinds” and other war crimes in Iraq, where her office says the number of those killed in recent days may run into the hundreds.
Ms Pillay said her office has received reports that militants rounded up and killed Iraqi army soldiers as well as 17 civilians in a single street in Mosul.
Her office is hearing of “summary executions and extra-judicial killings” as Isis militants overran Iraqi cities and towns this week, the statement said.
“I am extremely concerned about the acute vulnerability of civilians caught in the crossfire, or targeted in direct attacks by armed groups, or trapped in areas under the control of Isis and their allies,” Ms Pillay said.
“And I am especially concerned about the risk to vulnerable groups, minorities, women and children.”
Mr Obama did not specify what options he was considering, but he ruled out sending American troops back into combat in Iraq.
Shiite powerhouse Iran signalled its willingness to confront the growing threat from the militant blitz.
Iran’s official IRNA news agency reported former members of Tehran’s Revolutionary Guard have announced their readiness to fight in Iraq against Isis.
Iran has built close political and economic ties with postwar Iraq, and many influential Iraqi Shi’ites have lived for stretches of time in the Islamic Republic.
Militants driving in machine gun-mounted pick-ups entered the two newly-conquered towns in Diyala province late on Thursday – Jalula, 80 miles, northeast of Baghdad, and Sadiyah, just 60 miles north of the capital.
Residents of Jalula said the gunmen issued an ultimatum to the Iraqi soldiers not to resist and give up their weapons in exchange for safe passage. After seizing the town, the gunmen announced on loudspeakers that they had come to rescue residents from injustice and that none would be hurt.
The leader of Isis, Abu Bakr al-Baghdadi, is an enigmatic character said to mask his face, even in the presence of his aides.
Dubbed the “next” Osama Bin Laden, there is a $10 million bounty on his head.
Baghdad authorities have tightened security around the capital and residents are stocking up on essentials.
The Islamic militants also declared they would impose Shariah law in Mosul, which they captured on Tuesday, and other areas they seized, with savage punishments for crimes.
Online video showed Isis fighters holding a parade in a Mosul neighbourhood, with many of the gunmen cruising in vehicles seized from Iraqi forces.