and combined the explosives in tin cooking-oil cans for a more powerful blast. By combining the explosives from several mines and placing them in tin cans, the insurgents made them more powerful, but sometimes also easier to detect by Soviet sappers using mine detectors. After an IED was detonated, the insurgents often used direct-fire weapons such as machine guns and rocket-propelled grenades to continue the attack. Afghan insurgents operating far from the border with Pakistan did not have a ready supply of foreign anti-tank mines. They preferred to make IEDs from Soviet unexploded ordnance. The devices were rarely triggered by pressure fuses. They were almost always remotely detonated. Since the 2001 invasion of Afghanistan, the Taliban and its supporters have used IEDs against NATO and Afghan military and civilian vehicles. This has become the most common method of attack against NATO forces, with IED attacks increasing consistently year on year; according to a report by the Homeland Security Market Research in the US, the number of IEDs used in Afghanistan had increased by 400 percent since 2007 and the number of troops killed by them by 400 percent, and those wounded by 700 percent. It has been reported that IEDs are the number one cause of death among NATO troops in Afghanistan. Beginning in July 2003, the Iraqi insurgency used IEDs to target invading coalition vehicles. Many of these IEDs were made from military explosives looted from munitions bunkers following the 2003 invasion, such as landmines stripped of their explosives, 155-millimetre artillery shells rigged with blasting caps and modified aviation bombs of 500 lb or more, detonated by systems such as pull-wires and mechanical detonators, cell-phones, garage-door openers, cables, radio control (RC), and infrared lasers among others. To counter increasing armor protection, the insurgents have also developed IEDs that make use of explosively formed projectiles (EFPs); these are essentially cylindrical shaped charges usually constructed with a machined concave metal disc (often copper) facing the target, pointed inward. The force of the shaped charge turns the disc into a high velocity slug, capable of penetrating the armor of most enemy vehicles. Commonly positions for IEDs include on utility poles, road signs or trees, buried underground or in piles of garbage, disguised as rocks or bricks, and even inside dead animals. Typically they explode underneath or to the side of the vehicle, however, IEDs in elevated positions such as on road signs