Musannaf Ibn Abi Shayba 18:1135

Abu Bakr narrated to us, he said: Muhammad ibn Abi ‘Adi narrated to us, from Ash’ath, from al-Hasan, regarding a group of people who were competing in archery and struck a person, and it is not known which one of them struck him. He said: The blood money (diyah) is upon all of them.