Kenyan police seized landmines and homemade explosive devices Friday in Dadaab, the world\'s largest refugee camp and site of several attacks and blasts in recent months. \"This is a major breakthrough in our investigations because we have been looking for the source of the explosive materials used here. We conducted a raid and recovered nine landmines,\" said regional police chief Leo Nyongesa. \"We also recovered other improvised explosive devices,\" he said, adding that three women were being questioned. The expolosives were found in the Ifo section of the Dadaab complex in northern Kenya, home to some 450,000 mainly Somali refugees seeking shelter from drought, hunger and conflict. Dadaab, some 100 kilometres (60 miles) from Somalia, is in a border region that has seen a surge in attacks since Nairobi sent troops into its neighbour in October to battle Al-Qaeda linked Shebab insurgents. The attacks are often blamed by the authorities on sympathisers of Shebab militants, who control large parts of central and southern Somalia. Gunmen seized two Spaniards working for Medecins Sans Frontieres (Doctors Without Borders) from Dadaab in October and are thought to have taken them to Somalia.