There have been very few major engagements since the battle for the Euphrates river valley, Al Anbar, in May and November 2005. But that didn't mean the well trained units of insurgents were all destroyed. Sunni Arab militant groups suspected of ties to Al Qaeda in Mesopotamia established training camps east of Baghdad that turned out well-disciplined units willing to fight American forces in set-piece battles. American paratroopers fought such units in a pitched battle in the village of Turki in the volatile Diyala province, near the Iranian border.