Iraqi Shia militias and Kurdish forces are continuing their advance against Islamic State militants after breaking the siege of Amerli in northern Iraq.
A BBC team entered the town on Monday, finding residents who had endured more than two months under siege.
The joint forces have also seized the militant stronghold of Suleiman Beg.
Meanwhile Amnesty International says that it has uncovered new evidence that Islamic State have launched a campaign of ethnic cleansing in the north.
"The Islamic State (IS) is carrying out despicable crimes and has transformed rural areas of [the northern region of] Sinjar into blood-soaked killing fields in its brutal campaign to obliterate all trace of non-Arabs and non-Sunni Muslims," Amnesty's Donatella Rovera said.
The UN is sending a team to Iraq to investigate "acts of inhumanity on an unimaginable scale".
Violence in Iraq has escalated dramatically in recent months as IS, formerly known as Isis, and allied Sunni rebels have taken control of large parts of northern and western Iraq.
Thousands of people have been killed, the majority of them civilians, and more than a million have been forced to flee their homes.
Residents in Amerli were threatened with a massacre after resisting IS. The BBC's Gabriel Gatehouse, who entered the town on Monday, found residents happy to be reunited with their families.
They told him there was a huge amount of work to do to get back to normal.
Our correspondent says there are still pockets of IS resistance in the area, meaning that travel to the town remains problematic.
Outgoing Prime Minister Nouri Maliki, who visited Amerli on Monday, said: "Our enemy is retreating and our security forces backed by volunteers are advancing to purge further towns."
Correspondents say the recent advances are the biggest success by Iraqi and Kurdish forces against IS in recent months.
Kurdish peshmerga forces raised their flag in the town of Suleiman Beg on Monday.
AFP news agency reported that nearby Yankaja was also surrounded, and that militants there were being bombarded with artillery and machine-gun fire.
The militias said that Iran had played a role in the recent operations, supplying weapons and helping with military planning.
Some 15,000 minority Shia Turkmen had been holding out in Amerli, and the UN had expressed fears there could be a massacre if IS captured it.
IS has been accused of atrocities in areas of Iraq and Syria under its control, and sees minorities like the Shia Turkmen as apostates.
Amnesty says that it has gathered evidence that several mass killings took place in Sinjar in August, two of the deadliest of which took place when IS fighters raided villages and killed hundreds on August 3 and August 15.
"Groups of men and boys including children as young as 12 from both villages were seized by IS militants, taken away and shot," the UK-based human rights group says.
"There was no order, they [the IS fighters] just filled up vehicles indiscriminately," one survivor of the massacre told Amnesty.
On Monday the UN Human Rights Council agreed to send an emergency mission to investigate crimes allegedly carried out by IS.
Deputy Human Rights Commissioner Flavia Pansieri told the council that Christian, Yazidi, Turkmen, Shabak, Kaka'i, Sabean and Shia communities had "all been targeted through particularly brutal persecution".
Yazidis have been targeted for extremely harsh treatment. Many men who refused to convert to Islam were reportedly executed, while women and young girls were allotted as slaves to IS fighters.