'Dirty bomb'
Simply put, a dirty bomb is a powerful bomb with radioactive material packed around it. The radioactive materials are usually spent uranium rods form nuclear power stations supplied by nations who support terrorists and terrorism. A thick coating surrounds the bomb. This coating is there to protect the terrorist from the radiation of the materials inside the bomb. When detonated the bomb scatters the radioactive materials in its vicinity, killing a large number of people or soldiers before it is discovered that the bomb had radioactive materials with it. The radioactive debris can also damage electronic equipment it comes to contact with. These radioactive debris are hard to clean up and can spread even further by the wind. In other words it is simple but very effective. Such a weapon can be used on a small scale, and effectively do some damage.