The SAS is after a ruthless Taliban sniper who has shot dead seven British soldiers in Afghanistan. An elite squad was deployed after the skilled gunman took out three top sharp-shooters trying to end his reign of terror. One was killed by a single bullet between his eyes. The youngest is thought to be 19. Top brass fear time is running out before the sniper strikes again in Sangin, Helmand. A senior British Army officer said: Hes giving us real problems and weve not yet worked out how to take him down. SAS troops hunting the sniper were last night ordered to kill on sight. The are desperately trying to hunt down the master marksman before his terrifying death toll rises further. He is believed to have struck many times in Sangin, Helmand Afghanistans deadliest town. Three of his victims were sharpshooters who were among the best in their field. A senior British Army officer, who asked to remain anonymous, said: Our snipers are some of the best trained and capable soldiers we have. When you lose one it is telling you something. The Taliban sniper must watch our guys for days to wait for the best situation to open fire and still make his escape. So far he has not been taken down, even though the SAS have carried out several forays into the area. The SAS is working alongside the Special Reconnaissance Regiment the newest special forces unit set up in 2004. The SRR was formed from Britains most hush-hush unit 14 Intelligence. It has the most highly trained troops in staying hidden for long periods. Once they think they have spotted their target they will call in the SAS. Soldiers from 3rd Battalion, The Rifles, fear the sniper could only have been trained to such a standard outside Afghanistan. The British Army officer added: The conclusion is the Taliban have outside help from either Iran or al-Qaeda in Pakistan. The terrifying stand-off has been compared to Hollywood movie Enemy at the Gates. In the war film, Jude Law and Ed Harris play rival Soviet and German snipers stalking each other across Stalingrad during the Second World War. British snipers use a soaring watchtower at Forward Operating Base Jackson overlooking Sangin. They also use specialist Javelin-guided missiles, which can accurately blast any enemy positions they detect. Snipers are increasingly playing a bigger role in the vast desert of Helmand, where around 8,000 British soldiers are stationed. Around 25 British marksmen are employed in the area to target Taliban commanders, insurgent snipers or individuals linked to al-Qaeda. Deployed in two-man teams of a shooter and spotter, they often swap roles to avoid tired eyes. Heavy casualties in Sangin have forced chief of the defence staff Sir Jock Stirrup to demand a review of British tactics. It is understood up to 53 British troops have been killed in and around the Taliban stronghold over the past year. Since last November, 3 Rifles have lost seven soldiers in the district to small arms fire, while 15 troops have been killed by roadside bombs. The unit it replaced lost all but one of its fatalities to bombs during its tour of Sangin. But Afghanistan operations spokesman Major-General Gordon Messenger said: We categorically retain the initiative in the contest against the Taliban in the area. A dangerous enemy.. and hard to eliminate Taliban snipers have been operating in Helmand Province since 2006. A trained sniper with the ability to hide and blend into the environment can be very difficult to kill – and worrying for a British unit. He can keep a company of 130 men busy for weeks, chipping away at morale with his marksmanship. But British snipers are the best in Afghanistan and have scored many hits against insurgents. In 2007 Lance Corporal “Teddy” Ruecker, of 1 Royal Anglian, had a record 19 Taliban kills. In Kajaki, northern Helmand, in 2007 I met soldiers in his regiment who believed a Taliban sniper was operating nearby. The company commander dispatched Teddy and other marksmen to find the sniper, who was close to hitting Brits from well over 500m. He would fire, then disappear, evading devastating mortar salvos. The company found his lairs: intricate tunnels or “killing holes” dug in thick walls. They even found a snake the sniper killed with a knife as he lay in the dirt. Perhaps a veteran of Chechnya or Afghanistan’s 80s war, he fired from deep inside buildings, a damp cloth on his rifle hiding “muzzle flash” making him very hard to find. After weeks they got him, but it took a jet airstrike. A man and a rifle against so much firepower: it shows how much effect one marksman can have.