Nigeria\'s secret police said Monday it is holding over 100 leaders and members of a northern-based \"dissident\" group it did not name. Parts of northern Nigeria have in recent months been hit by frequent attacks staged by a radical Islamist sect Boko Haram. \"Successful security operations have led to the arrest of some identified key cell commanders and members of the dissident group in Bauchi, Borno, Kaduna, Kano, Yobe and Adamawa states,\" State Security Service (SSS) spokesperson Marilyn Ogar told reporters. She declined to name the group nor indicate the numbers involved. \"I know we have arrested over a hundred.\" An extremist sect, Boko Haram, based in northeastern Borno state, has in recent months unleashed a reign of terror in parts of northern Nigeria, bombing and shooting targeted spots and individuals. It also bombed the national police headquarters in the capital Abuja last month. The group started last year with drive-by shootings of mainly policemen and other community or institutional leaders. Lately the attacks have increased in frequency and magnitude, killing dozens of people in recent months. Ogar\'s statements did not suggest any plans to prosecute the arrested because of what she described as President Goodluck Jonathan\'s new \"carrot and stick approach\" to the unrest. \"For strategic operational reasons, details of those arrested will remain classified as they are still undergoing the process of de-radicalisation, perception management...,\" Ogar said. She said: \"You must also realise that they are Nigerians and being Nigerians, for whatever reasons they have gone overboard, we have to first of all try to engage them and talk them out of those reasons.\" Boko Haram has claimed responsibility for most of the bombing attacks in northern Nigeria and the capital. The sect has in the past year carried out bombings and shot leading figures targeting military and police personnel, community and religious leaders as well as politicians. Boko Haram -- the name means \"Western education is sin\" -- launched an uprising in 2009 which was put down by a brutal military assault that left hundreds dead, most of them members of the sect.