Musannaf Ibn Abi Shayba 18:890

Abu Bakr narrated to us, he said: Muhammad ibn Bishr narrated to us, he said: Sa’id narrated to us, from Abu Ma’shar, from Ibrahim, he said: If one is killed in the Sacred Territory (al-Balad al-Haram) or outside the Sacred Territory, the blood money (diyah) is one and the same.