Iraqi forces battle to drive jihadists from Saddam's home town

Iraqi forces launched an offensive on Tuesday to drive Islamic State fighters out of Tikrit, home town of executed dictator Saddam Hussein, while the militants warned they would attack Americans "in any place."

In Geneva, the United Nations refugee agency announced a major aid operation to get supplies to more than half a million people displaced by fighting in northern Iraq.

Buoyed by an operation to recapture a strategic dam from the jihadists after two months of setbacks, Iraqi army units backed by Shi'ite militias fought their way towards the center of Tikrit, a city 130 km (80 miles) north of Baghdad which is a stronghold of the Sunni Muslim minority.

Baghdad is now trying to turn the tide after the Kurds said they had taken the dam, easing fears that the militants could cut off electricity and water supplies, or even breach the structure, causing huge loss of life and damage down the Tigris.

Efforts are underway in Baghdad to form a new government that will unite the majority Shi'ites with the Sunnis and Kurds in halting the Islamic State insurgency that threatened to tear the country apart.

Sunnis long dominated Iraq until the U.S.-led invasion forced Saddam to flee. He was captured near Tikrit in late 2003 and executed in 2006.