(Al-Baqara) 2 : 191
وَاقْتُلُوهُمْ حَيْثُ ثَقِفْتُمُوهُمْ وَأَخْرِجُوهُمْ مِنْ حَيْثُ أَخْرَجُوكُمْ ۚ وَالْفِتْنَةُ أَشَدُّ مِنَ الْقَتْلِ ۚ وَلَا تُقَاتِلُوهُمْ عِنْدَ الْمَسْجِدِ الْحَرَامِ حَتَّىٰ يُقَاتِلُوكُمْ فِيهِ ۖ فَإِنْ قَاتَلُوكُمْ فَاقْتُلُوهُمْ ۗ كَذَٰلِكَ جَزَاءُ الْكَافِرِينَ
And you slay them wherever you catch them, and you expel them from wherever they have expelled you, and sedition is more serious than slaying. And you don’t fight them at the Sacred Masjid unless they are fighting you in it. If they fight you, then you fight them back, that is the reward for the disbelievers.