KABUL (AFP) - More than 1,000 British, Afghan and US troops launched a fresh offensive in a key battleground of southern Afghanistan on Friday, after President Barack Obama unveiled a new strategy to end the war. Nato said the offensive was designed to crush insurgents around a major town in Helmand in order to allow development to begin and civilians to return - key elements of Obamas decision to deploy 30,000 new US troops to Afghanistan. Many of the new forces are heading south, where Helmand is the heartland of Afghanistans massive opium production and a stronghold for the eight-year Taliban insurgency seeking to overthrow the Western-backed govt. More than 1,000 Isaf personnel partnered with Afghan national security forces began a long-planned operation in northern Helmand province to clear insurgent forces from a key area, the military said. Around 900 US Marines and sailors, British troops and more than 150 Afghan soldiers and police were taking part in Operation Khareh Cobra, or Cobras Anger in the valley of Now Zad, it added. So far, four Taliban dead bodies were left behind on the battlefield. But enemy casualties could be higher, Helmand Governor spokesman Daud Ahmadi told AFP, adding that scores of mines and a cache of explosives were seized. Yusuf Ahmadi, a Taliban spokesman, confirmed the militia was fighting back and claimed that the insurgents had inflicted losses on the soldiers. Helmand produces about 50pc of the worlds opium. Its largely unguarded southern border with Pakistan is both a route for the illicit drug trade and for a steady supply of Taliban recruits and supplies. Now Zad was once Helmands second-largest city, but is now empty due to years of fighting, Isaf said.