Narrated Anas:
The people of the tribes of Ril, Dhakwan, 'Usiya and Bani Lihyan came to the Prophet (s.a.w.a.) and claimed that they had embraced Islam, and they requested him to support them with some men to fight their own people. The Prophet (s.a.w.a.) supported them with seventy men from the Ansar whom we used to call Al-Qurra'(i.e. Scholars) who (out of piety) used to cut wood during the day and pray all the night. So, those people took the (seventy) men till they reached a place called Bi'r-Ma'ana where they betrayed and martyred them. So, the Prophet (s.a.w.a.) invoked evil on the tribe of Ril, Dhakwan and Bani Lihyan for one month in the prayer.
Narrated Qatada: Anas told us that they (i.e. Muslims) used to recite a Quranic Verse concerning those martyrs which was:-- "O Allah! Let our people be informed on our behalf that we have met our Lord Who has got pleased with us and made us pleased." Then the Verse was cancelled.
Anas b. Malik reported that the Messenger of Allah (s.a.w.a.) observed Qunut for one month Invoking curse upon Ri'l, Dhakwan, 'Usayya. those who disobeyed Allah and His Messenger (s.a.w.a.).
Anas reported that the Messenger of Allah (s.a.w.a.) observed Qunut for one month invoking curse upon some tribes of Arabia (those who were responsible for the murders in Bi'r Ma'una and Raji'), but then abandoned it.
It was narrated from Anas:
"The Messenger of Allah (s.a.w.a.) said the Qunut for a month."- (One of the narrators) Shu'bah said: "He cursed some men." Hisham said: "He supplicated against some of the tribes of Arabs."-"Then he stopped doing that after bowing." This is what Hisham said. Shu'bah said, narrating from Qatadah, from Anas that the Prophet (s.a.w.a.) said the Qunut for a month, cursing Ri'l, Dhawkan and Lihyan.