The US detected the buildup, and on March 2, 2002, US, Canadian, and Afghan forces began "Operation Anaconda" against them. The trucks of Task Force Hammer become stuck in the mud while owing to a communications mistake, the massive aerial bombardment did not take place. The poorly trained Afghan government troops proved incapable of fighting al-Qaeda without air support. Mujahideen forces, using small arms, rocket-propelled grenades, and mortars, were entrenched into caves and bunkers in the hillsides largely above . They used "hit and run" tactics, opening fire and then retreating to their caves and bunkers to weather the return fire and bombing. US commanders initially estimated their opponents as an isolated pocket numbering fewer than 200. Instead the guerrillas numbered between 1,000–5,000, according to some estimates. By March 6, eight American, seven Afghan allied, and up to 400 Al Qaida opposing fighters had been killed. At one point, while coming under heavy al-Qaeda force, the Afghan government forces fled in panic and refused to fight, leading to the men of Task Force Hammer to take on al-Qaeda alone. "Friendly fire" incidents where American troops were bombed by their air force several times added to further difficulties. Sub-engagements included the Battle of Takur Ghar on 'Roberts Ridge,' and follow-up Operations Glock and Polar Harpoon.