MARJAH // Squads of Marines and Afghan soldiers slowly pressed deeper into the Taliban stronghold of Marjah today, painstakingly clearing out booby-trapped houses one by one. Improvised bombs and mines slowed the advance of thousands of US, British and Afghan soldiers in Nato's most ambitious effort yet to break the militants' grip over their southern heartland. Using metal detectors and sniffer dogs, US forces found caches of explosives rigged to blow as they went from compound to compound. They also discovered several sniper positions, freshly abandoned and booby-trapped with grenades. Nato said it hoped to secure Marjah - the largest town under Taliban control and a key opium smuggling hub - within days, set up a local government and rush in development aid in a first test of the new US strategy for turning the tide of the eight-year war. The offensive is the largest since the 2001 US-led invasion of Afghanistan. At least two shuras, or meetings, have been held with local Afghan residents - one in the northern district of Nad Ali and the other in Marjah itself, Nato said in a statement. Discussions have been "good," and more shuras are planned in coming days as part of a larger strategy to enlist community support for the Nato mission. Afghan officials said today that at least 27 insurgents had been killed in the operation. Helmand government spokesman Daoud Ahmadi said troops found a large cache of bomb-making materials in one compound in Marjah. Most of the Taliban appeared to have scattered in the face of overwhelming force, possibly waiting to regroup and stage attacks later to foil the alliance's plan to stabilise the area and expand Afghan government control in the volatile south. Two Nato soldiers were killed on the first day of the operation - one American and one Briton, according to military officials in their countries.