Said the Shaykh in his commentary on Riyâdus-Sâlihîn, Hadith 31
'As for what some people do today viz. committing suicide (in warfare) whereby one of them will wrap some explosives to his body then go to the midst of the Kuffâr then detonate the explosives. The act is taking one's life, we seek refuge in Allâh. Whoever takes his own life will abide forever in the Hellfire as it has come in a hadith of the Prophet – SallaLlahu alahye wa sallam. The person has only killed himself and this is not in service to Islam; he just killed himself and killed some other ten, or one hundred or two hundred (Kuffâr); he has brought no good to Islam with that…it often occurs that the harm thereof is greater that the (presumed) benefit. [An example of that] is what goes on between the Jews and the Palestinians; whenever a person dies among the Jews due to a suicide bomb attack (from the Muslims), or he kills six or seven, the Jews will in turn kill about sixty (Muslims) or more. With that, there is no benefit for Islam; it is even unhelpful to the cause of those who blow themselves up. This is why we say suicide bombing is indeed an act of taking one's life unjustly, it is a means of entering the Hell – we seek refuge in Allâh. Whoever carries out the act is never a martyr. A person who does this relying on some textual interpretations thinking that it is permissible, we hope he will be saved from the sin thereof, but there is no martyrdom for him because he did not take the correct path to it. Whoever strives (with knowledge) and makes a mistake will have one reward.'