More than 100 Iraqi men, including nine boys, have been abducted by Islamic State of Iraq and the Levant (ISIL) fighters near Tikrit, an influential sheikh says.

Sheikh Anwar Assi al-Obeidi told Al Jazeera on Wednesday that 118 men and nine boys were originally captured three days ago from Rubaidha village, east of Tikrit, but that 21 men have since been released.

The boys, aged nine and 10, are still being held along with the remaining men at an unknown location, Sheikh Anwar said.

He said that most of those captured have relatives fighting against ISIL and that 600 members of the al-Obeid tribe, where he is the paramount sheikh, have been killed by ISIL fighters since June.

"ISIL have taken our men in retaliation for their support to the security forces and being part of the Sunni tribes that oppose ISIL’s ideology," the sheikh said.

"This is an attempt by ISIL to mount pressure on their relatives and family members whom have taken up arms against ISIL."

He said news of the abductions had not been reported earlier because phone services had been cut off in the area.

The news came a day after ISIL fighters reportedly captured at least 70 Assyrian Christians in Hassakeh province in northeast Syria.

A new UN report released this week documented widespread human rights violations committed by ISIL in Iraq between September and December last year.

“Members of Iraq’s diverse ethnic and religious communities, including Turkmen, Shabaks, Christians, Yazidi, Sabaeans, Kaka’e, Faili Kurds, Arab Shia, and others have been intentionally and systematically targeted by ISIL and associated armed groups and subjected to gross human rights abuses," the report said.