KABUL (Reuters) - US Marines pressed into a remote Taliban stronghold on Saturday with their first major assault in Afghanistan since President Barack Obama earmarked 30,000 more troops to try to turn the tide on the Taliban insurgency. Operation Cobras Anger, which involves 900 US Marines and sailors, British troops and 150 Afghan soldiers and police, pushed into the Now Zad district of southern Helmand province, an insurgent stronghold depopulated after years of heavy fighting. The advancing Marines killed several militants and seized bombs and weapons on the first day of the operation, which began with an airborne assault on Friday, said Major Bill Pelletier, spokesman for the Marine Expeditionary Brigade in Helmand. Among other things found yesterday evening ... two or three weapons caches and IED-making materials, mortars, small arms machine-guns and light weapons were seized, he said. The operation is continuing today in an area that had an enemy presence. We are going to disrupt that presence. Pelletier said there were no casualties among foreign or Afghan govt forces and he could not be specific on the exact number of insurgents killed. British forces were flanking the Marines to the eastern side of the battle area, a spokesman for the British military in Helmand said, declining to say how many British troops were involved for operational security reasons. Now Zad has been one of the most bitterly contested districts of Afghanistans most violent province since British forces first moved into the area in 2006. Nearly all of its 30,000 residents have fled. A company of US Marines is based in the town but much of the surrounding valley is in ruins, held by Taliban fighters and sown with bombs.