Islam clearly prohibits both suicide and killing of innocents.
“O ye who believe!… [do not] kill yourselves, for truly Allah has been to you Most Merciful. If any do that in rancour and injustice, soon shall We cast him into the Fire…” (Qur’an 4:29-30).
“And fight in the way of God against those who fight you. But do not transgress the limits. Truly God does not love transgressors.” (Surah 2:190)
“And do not spread discord on the (face of the) earth”(Surah alBaqarah V. 60)
The Quran clearly states that the killing of (even) one innocent person is equivalent to massacre of all humankind because it is like opening the floodgates that creates a situation beyond anyone’s control; while saving one life is equivalent to the rescue of all humankind.
Our Prophet Mohammad (PUBH) has said that Allah takes mercy upon those who take mercy upon fellow human beings. You treat the inhabitants of earth with compassion and the inhabitant of Heaven (Allah) shall show compassion towards you (Tirmizi, Abu Dawood).
Hazrat Abu Bakr, the first leader of Islam after Prophet Muhammad, gave these commandments prior to dispatching army to Syria in battle against Roman Empire. This also established the conduct of war for later Muslim generations:
“Stop, O people, that I may give you ten rules to keep by heart: Do not commit treachery, nor depart from the right path. You must not mutilate, neither kill a child or aged man or woman. Do not destroy a palm tree, nor burn it with fire and do not cut any fruitful tree. You must not slay any of the flock or herds or the camels, save for your subsistence. You are likely to pass by people who have devoted their lives to monastic services; leave them to that to which they have devoted their lives. You are likely, likewise, to find people who will present to you meals of many kinds. You may eat; but do no forget to mention the name of God.”
A fatwa was issued against suicide attack. It says “suicide bombings and attacks against civilian targets are not only condemned by Islam, but render the perpetrators totally out of the fold of Islam, in other words, to be unbelievers”. “They can’t claim that their suicide bombings are martyrdom operations and that they become the heroes of the Muslim ummah [nation], no, they become heroes of hellfire, and they are leading towards hellfire,” he said. “There is no place for any martyrdom and their act is never, ever to be considered jihad [holy war],” he said. “Terrorism is terrorism, violence is violence and it has no place in Islamic teaching and no justification can be provided for it, or any kind of excuses or ifs or buts.”
Abdul Rahman Al-Sudais, Imam of Makka’s Grand Mosque in Saudi Arabia, has also denounced terrorism saying No Room for Terrorism in Islam. He also condemned suicide bombing as ‘haram’ and un-Islamic.