(Recasts with more comment) By Peter Graff GARMSER, Afghanistan, Dec 5 (Reuters) - British Marines attacked a Taliban-held valley in southern Afghanistan on Tuesday but pulled back after a ferocious counterattack that triggered air strikes and artillery fire, witnesses said. One Royal Marine was killed and a second wounded during the battle, the UK Helmand Task Force (UKTF) said. Scores of soldiers ran across a bridge over the Helmand River under a full moon shortly before daybreak and began sweeping south through wheat fields in the south of the province, the opium centre of the world's major producer. A Reuters cameraman said the Marines initially faced only sporadic resistance but when they advanced, Taliban fighters launched a ferocious, organised riposte with heavy weapons and tried to outflank the British troops. The fierce resistance illustrated the challenges facing the NATO troops in Afghanistan where they are trying to subdue well-armed Taliban and other militants bolstered by profits from a record opium crop, according to Afghan and foreign officials. Major Andy Plewes, who led the Royal Marines of Zulu Company 45 Commando, on the assault said he considered it a success as they had cleared out areas near the "D.C.", a tiny strip of road and ruined buildings on the eastern side of the Helmand River. "As far as we are concerned, the Royal Marines achieved their objectives today and will reassess their future operations," said Lieutenant Colonel Andy Price, UK forces spokesman in Afghanistan. The 32,000-strong force NATO-led International Security Assistance Force took over command of the war against the Taliban from U.S.-led forces in October and has launched a string of offensives. British casualties have been mounting since ISAF took over command of operations in southern Afghanistan at the end of July. Britain has lost 42 soldiers since the Taliban government was toppled in 2001, the bulk of them this year. Plewes said the Marines had expected resistance: "What we didn't know was how strong it was." "We were prepared for it which is why we were able to hold them off and move safely back to the (district centre of Garmser)," he told a Reuters reporter with the Marines. "We don't currently have enough forces in the area to hold ground completely and that has to be done by Afghan security forces." BARRAGE OF AIR STRIKES The British forces, who make up the bulk of NATO forces in Helmand, opened fire from light armoured vehicles and engaged small groups of guerrillas with mortars and machine guns. Afghan police and soldiers have so far held just the bridgehead and the short road at the north end of the valley, criss-crossed by networks of ancient canals that make Helmand fertile enough to produce a third of the world's opium crop. The Taliban faced barrages of air strikes from Apache helicopters, 500 pound bombs dropped by B1 bombers and withering cannon fire from A-10 attack jets before the British finally pulled back after a 10-hour battle. The Taliban fighters, who say they have the expertise to defeat the strongest army, had dug sophisticated networks of trenches often leading from compound to compound. This year has seen the worst fighting since U.S.-led forces ousted the Taliban's strict Islamist government in 2001. About 4,000 people have died, a quarter of them civilians. The alliance troops were deployed to aid reconstruction and to help Afghanistan's government by build stability. But they have been increasingly drawn into battles with the Taliban and other militants in the opium poppy-growing south.
