The Islamic State group has been unable to conquer the neighbourhood of Jubur, named for the tribe that resides there, in the Sunni Arab town of Dhuluiyah 90 kilometres (55 miles) north of Baghdad.
"They attacked Jubur from three directions last night and the clashes lasted until morning," said a senior police officer in Dhuluiyah.
"Their attack was unsuccessful but there were casualties," he said, seven in each camp, including a jihadist fighter who detonated a suicide vest.
A medic in the nearby town of Balad confirmed that the hospital there had received the bodies of seven fighters killed by the jihadists overnight.
Jubur, which played a prominent role in the formation of US-backed Sunni tribal forces to combat IS's previous incarnation in 2005-2007, has received support from the Iraqi army and allied militias.
Its leaders say the neighbourhood needs more assistance, including air strikes from the US-led international coalition bombing jihadist targets in other parts of Iraq.