An Iraqi military helicopter was shot down by suspected jihadist fighters Wednesday, five days after a similar incident in the same location north of Baghdad, officers said.
The helicopter was a Bell 407 flying back from the Baiji refinery, 200 kilometres (120 miles) north of Baghdad, where federal forces have been fending off Islamic State fighters for four months.
An aviation officer told AFP both pilots, two majors, were killed in the attack over Seiniye, west of Baiji.
"They were on a security mission and coming back from the refinery. They flew above the wreckage of the other helicopter," he said, speaking on condition of anonymity.
A Russian-made Mi-35 was shot down on Friday in the same area.
"They spotted a unit of militants and requested authorisation to engage. They were initially told not to but they insisted, arguing it was an easy target," the officer said.
"They were eventually given the green light but when they lowered their altitude, they were shot at. Their helicopter came down almost exactly where the other one did," he said.
A senior source in the military confirmed both crew members had died.
A resident, who said the incident occurred at around 9:00 am (0600 GMT), described the helicopter as "completely charred".
Iraq last year received the last of 30 Bell 407 helicopters from the United States. They are designed as commercial helicopters but can be armed with machine guns and Hellfire missiles.
Iraqi federal forces have been battling the Islamic State group at the Baiji oil refinery since the beginning of the jihadist offensive in early June.