Four US Marines died in an Afghan battle after their commanders rejected requests for artillery fire under new rules designed to protect civilians, US media reported Wednesday. A team of Marines made repeated appeals for air and artillery support after coming under fire in the village of Ganjgal in eastern Kunar province on Tuesday, McClatchy newspapers reported. US commanders declined the request for artillery fire, citing new rules that seek to minimize civilian casualties, a McClatchy journalist accompanying the American unit reported. Air power, in the form of helicopters, only arrived after more than an hour 'despite earlier assurances that air cover would be five minutes away,' McClatchy's Jonathan Landay wrote. The top commander of US and NATO forces in Afghanistan, General Stanley McChrystal, has issued new rules for combat and the use of air raids in a bid to prevent civilian deaths. McChrystal has warned that civilian casualties caused by the NATO-led force risk alienating the Afghan population and jeopardizing the war effort. But the general and other top military officials have said air support and fire power would not be restricted when US troops were under direct threat. Tuesday's firefight in eastern Afghanistan involved a 13-member team of US Marine and Army trainers assigned to the Afghan national army, the report said. Eight Afghan soldiers and police and an Afghan interpreter also died in the battle, which lasted for hours with insurgents unleashing a barrage of gunfire and rockets from mountain positions, the report said. When an Afghan soldier demanded helicopter gunships, US Major Kevin Williams replied through an interpreter: 'We are pinned down. We are running low on ammo. We have no air. We've lost today.' The Americans were assisting Afghan forces in an operation that called for Afghans searching the hamlet for weapons and then meeting village elders to plan police patrols. But US officers suspected insurgents were tipped off about the operation ahead of time, as the coalition and Afghan forces were ambushed as they approached the outskirts of the hamlet at dawn, the report said. 