The killings, all committed in public, raise the death toll suffered by the Sunni Al Bu Nimr tribe in recent days to some 150, suggesting IS fighters now view them as a threat.
Some Sunnis in the volatile province had previously supported the local expansion of IS and other militants in December.
Meanwhile, separate attacks around Baghdad killed at least 19 people, authorities said.
Today's attack on the Sunni tribe took place in the village of Ras al-Maa, north of Ramadi, the provincial capital. There, the militant group killed at least 40 men, six women and four children, lining them up and shooting them one by one, senior tribesman Sheikh Naim al-Gaoud told The Associated Press. The militants also kidnapped another 17 people, he said.
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Late Friday, IS fighters killed 50 members of the tribe, a day after killing 48 of them, according to various officials who have spoken to the AP.
IS militants have overrun a large part of Anbar province in a push to expand their territory across Iraq and Syria. Officials with the Iraqi government, as well as officials with the US-led coalition targeting the extremists, repeatedly have said that Iraqi tribes are key elements in the fight against IS since they are able to penetrate areas inaccessible to airstrikes and ground forces.
Since the Islamic State group's major offensive in Iraq, a number of Iraq's Sunni tribes have been fundamental in stalling its advance, taking up arms and fighting alongside Iraqi security forces.
Ramadi has yet to fall in part because of key Sunni tribes in the city. The Jughaifi and al-Bunimer tribes have helped Iraqi special forces protect the Haditha Dam in Anbar. In the battleground town of Dhuluiyah, the al-Jabbouri tribe has been the sole resistance to an IS militant takeover.