ReutersBAGHDAD - Islamic State insurgents ‘massacred’ some 80 members of Iraq’s Yazidi minority in a village in the country’s north, a Yazidi lawmaker and two Kurdish officials said.‘They arrived in vehicles and they started their killing this afternoon,’ senior Kurdish official Hoshiyar Zebari told Reuters. ‘We believe it’s because of their creed: convert or be killed.’ A Yazidi lawmaker and another senior Kurdish official also said the killings had taken place and that the women of the village were kidnapped.A push by Islamic State militants through northern Iraq to the border with the Kurdish region has alarmed the Baghdad government, drawn the first U.S. air strikes since the end of American occupation in 2001 and sent tens of thousands of Yazidis and Christians fleeing for their lives.Yazidi parliamentarian Mahama Khalil said he had spoken to villagers who had survived the attack. They said the killings took place during a one-hour period. The resident of a nearby village said an Islamic State fighter from the same area gave him details of the bloodshed.‘He told me that the Islamic State had spent five days trying to persuade villagers to convert to Islam and that a long lecture was delivered about the subject today,’ said the villager. ‘He then said the men were gathered and shot dead. The women and girls were probably taken to Tal Afar because that is where the foreign fighters are.’ That account could not be independently confirmed. Islamic State militants have killed at least 500 members of Iraq’s Yazidi ethnic minority during their offensive in the north, Iraq’s human rights minister told Reuters on Sunday. Mohammed Shia al-Sudani said the Sunni militants had also buried alive some of their victims, including women and children. Some 300 women were kidnapped as slaves, he added.Moreover, the BBC has reported that air strikes have targeted Islamic State (IS) fighters near north Iraq’s vital Mosul dam after reports of an operation to recapture it from the militants. US media say American fighters and drones were involved, and they were providing air cover to Iraqi and Kurdish troops on the ground. At least 11 IS fighters were killed, sources in Mosul told BBC News.The extreme Sunni group, which overran Mosul this summer, has been accused of a new massacre of non-Muslims. At least 80 men from the Yazidi faith were killed, and scores of women and children abducted, in the village of Kawju (also spelt Kocho) on Friday. Reports say the men were killed after refusing to convert to Islam. A US drone strike later destroyed two vehicles belonging to the militants.In another development, German Foreign Minister Frank-Walter Steinmeier visited Iraq, as Western states stepped up aid. Early reports suggested the aircraft which targeted the dam area could have been Iraqi but NBC, quoting US military officials, said they were US FA-18 fighter bombers and drones. ‘Sources told NBC News the decision to try retaking the dam came after intelligence showed Isis militants were not yet at a point where they could blow up the installation,’ it added. Reports of air strikes also came from residents living near the dam who spoke to AP news agency. A Kurdish news website, Rudaw, said the air strikes appeared to be the ‘heaviest US bombing of militant positions since the start of air strikes’ against IS last week. ‘Kurdish Peshmerga forces are expected to launch a ground assault to retake areas lost to the IS earlier this month,’ it said. Another US broadcaster, CNN, reported earlier that a ‘US and Iraqi military operation’ aimed at retaking the dam was scheduled to begin early on Saturday.The dam, captured by IS on 7 August, is of huge strategic significance in terms of water and power resources. Located on the River Tigris about 50km (30 miles) upstream from the city of Mosul, it controls the water and power supply to a large surrounding area in northern Iraq. Visiting Baghdad, Germany’s foreign minister met the new Prime Minister, Haider al-Abadi, who took over from Nouri Maliki this week.He said he hoped Mr Abadi would be able to represent all the different regions and religions in the country, as this was the only way to prevent disenchanted Iraqis from backing IS. German military transport planes have already begun delivering aid through the Kurdish city of Irbil but Germany is legally prevented from arming countries involved in conflict. Two Airbus flights carrying UK aid supplies arrived in Irbil on Saturday. On a stop in the city, Mr Steinmeier met Yazidi refugees. IS-led violence has driven an estimated 1.2 million Iraqis from their homes. Whole communities of Yazidis and Christians have been forced to flee in the north, along with Shia Iraqis, who IS do not regard as true Muslims.