Iraqi government forces and Shiite militiamen may have committed human rights violations in a major battle against the Islamic State last year, according to Human Rights Watch.

In a report by the Assyrian International News Agency (AINA), the Human Rights Watch (HRW) claimed that Iraqi government and Shiite soldiers may have abducted 11 civilians during a battle against the militants in the town of Amerli last year, and burned nearby villages.

The report alleged that at least 30 villages were looted and razed to the ground in a manner it described as "methodical and driven by revenge."

The HRW claimed that the victorious forces used fire, explosives and heavy machinery to wreak destruction on homes and structures. 

In addition, the report said that the civilians were abducted possibly on suspicion of aiding ISIS or simply for being part of the Sunni sect.

The human rights violations apparently occurred just after the battle of Amerli in August in which US aircraft assisted the besieged Iraqi soldiers and Shiite militia in breaking out of the militant siege of the town by dropping bombs on jihadist positions. The US government had praised the victory at Amerli as being one of the most important in countering the growth of the Islamic State, and an example of cross-sectarian cooperation.

Sarah Margon of the HRW called upon the governments of Iraq, Iran and the US to avoid the same atrocities as the battle for Tikrit rages.

Iraqi government forces, supported by Iranian-backed Shiite militias, are currently engaging the Islamic State in Tikrit. The offensive has been stalled because of heavy casualties among goverment soldiers.

"It's not just using airstrikes to loosen the grip of ISIS, but it's what happens in the aftermath," Margon, said according to AINA.  "While the United States may not be on the ground participating in those battles, they have an obligation to think about what's next."