Stanley McChrystal, the commander of U.S. and NATO forces in Afghanistan, apologized on national television Tuesday for an airstrike that killed almost two dozen people on Sunday.

"I pledge to strengthen our efforts to regain your trust to build a brighter future for all Afghans," McChrystal said. "I have instituted a thorough investigation to prevent this from happening again."

Meanwhile, The Associated Press reports that a direct route has been cleared that runs from the north to south of the Afghan town of Marja. That's a big breakthrough for the joint NATO-Afghan offensive. U.S. Marines and Afghan troops had been marching through insurgent fire and booby-trapped poppy fields for more than a week before they were able to meet and clear the route. Convoys will use the road to supply ammunition and reinforcements to troops.

Separately in Helmand province, an explosion killed eight people. Police report explosives in a parked motorcycle caused the blast.