All over the world, if you asked any known Muslim, what Quran said? The first answer that will come out of their mouth is, Killing the known Muslim, to earn reward of Allah, but little did they know that, Holy Quran the Muslims book strictly condemned killing of innocent people.
the condemnations was not by Mallam or Sheikh or any Islamic scholars, but a verse of Qur'an was dedicated to it.
Quran Chapter 2 verse 84, condemned shedding in innocent blood.
Read the verse below
وَإِذۡ أَخَذۡنَا مِيثَٰقَكُمۡ لَا تَسۡفِكُونَ دِمَآءَكُمۡ وَلَا تُخۡرِجُونَ أَنفُسَكُم مِّن دِيَٰرِكُمۡ ثُمَّ أَقۡرَرۡتُمۡ وَأَنتُمۡ تَشۡهَدُونَ
Wa-ith akhathna meethaqakumla tasfikoona dimaakum wala tukhrijoonaanfusakum min diyarikum thumma aqrartum waantum tashhadoon
And when We made with you a covenant (saying): Shed not the blood of your people nor turn (a party of) your people out of your dwellings. Then ye ratified (Our covenant) and ye were witnesses (thereto).
-Sura Al-Baqarah, Ayah 84OMOKOSHABAN