US ambassador urged Iraq's divided leaders to rein in militias on Saturday as political blocs failed again to break a deadlock on forming a unity government that they hope can avert civil war. Zalmay Khalilzad, who is pressing hard for a government more than three months after elections, issued a tough warning about the militias, many of which have ties to powerful Shiite leaders and are entrenched in Iraqi security forces and police. "More Iraqis are dying from the militia violence than from the terrorists," he told reporters during a visit to a Baghdad youth centre newly renovated with US funds. "The militias need to be under control." Iraq's Shiite, Kurdish and Sunni leaders held another round of talks aimed at resolving differences holding up formation of post-war Iraq's first full-term government. But there was no sign of a breakthrough. Sunni politician Tareq Hashemi said talks focused on ways of building a solid political foundation for the new government. The destruction of a Shiite shrine a month ago sparked a wave of reprisals that raised the prospect of pro-government Shiite militias pushing Iraq into civil war. The crisis has increased pressure to form a Cabinet that can avert an all-out sectarian conflict.