Seventeen killed in battles near Iraq's Baiji refinery

Seventeen people were killed in Iraq on Monday in clashes between Islamic State of Iraq and Syria (ISIS) and pro-government forces in a town close to the country's biggest refinery, a focal point in efforts to counter the ultra-hardline Sunni group.

The refinery beside the town of Baiji has changed hands before, reflecting the Iraqi army's struggle to hold territory it recaptures after months of clashes.

Fighting on Monday took place on a road used by ISIS for supply lines leading from Baiji to the nearby town of Siniya to the west.

Twelve militants, two government soldiers and three members of Shi'ite militias that provide vital support for the army were killed, a senior regional security official said.

Siniya is held by ISIS, which controls a third of Iraq, as well as parts of neighbouring Syria.

The group, which also holds territory in Libya and has sympathisers in Egypt, highlights the spread of ISIS since the 2011 Arab Spring uprisings that toppled veteran autocrats who had repressed hardline groups.

Iraq's government hoped to gain momentum after the army and its Shi'ite militia allies seized back Saddam Hussein's hometown of Tikrit in April following a month-long battle.

But the Shi'ite-led government faced a setback last month when the insurgents captured Ramadi, provincial capital of Anbar Province, the country's Sunni heartland.

Iraq's army, which has largely proven ineffective against the insurgents, relies heavily on Iranian-backed Shi'ite militias as well as on U.S.-led air strikes to try to slow the momentum of ISIS.

The group has used executions, sometimes videotaped, to strike fear into residents of areas it captures to try to sustain a self-proclaimed caliphate.

ISIS's territorial advances have exacerbated a sectarian conflict in Iraq, which is still struggling to find stability four years after the withdrawal of U.S. troops.

Iraq's civil war has generated steady allegations of human rights abuses on all sides, as well as concerns over a humanitarian crisis.

In a speech on Monday in Geneva, U.N. High Commissioner for Human Rights Zeid Ra'ad Al-Hussein accused ISIS of perpetrating "the most despicable abuses on the Iraqi people under its control".

"Countering extremism and addressing sectarian violence will require more than military action," he said.

"We stand ready to assist the government to promote the rule of law and good governance; increase accountability; encourage community reconciliation; and ensure respect for the rights of minorities and of women."