The US military said fighter jets and drones had conducted the strikes late on Saturday against "Islamic State" insurgents that were firing on Yazidi civilians near Sinjar in northern Iraq.

They were the third round of airstrikes since President Barack Obama authorized action on Thursday.

He said the strikes were aimed to prevent a possible "act of genocide" against displaced minorities forced to flee their homes, including thousands of Yazidis camping out in a mountain range near the Syrian border.

In a statement, US Central Command said that the first strike at 11:20 a.m. EDT (1520 UTC) on Saturday hit an armored personnel carrier. The second and third strikes 20 minutes later hit two more armored personnel carriers and an armed truck, with indications suggesting the "strikes were successful in destroying their intended targets," the statement said.

The fourth strike at 10 p.m. EDT (1900 UTC), struck another armored personnel carrier also in the Sinjar area.

Unfolding humanitarian disaster

The military action has helped clear the way for aid drops to thousands of starving civilians who've sought refuge in the Sinjar mountains. On Saturday night, US Central Command said it had made a third humanitarian aid drop with more than 3,800 gallons of water and 16,000 meals.

Britain was expected to make its first aid drop over the region on Sunday, with two British Royal Airforce transport planes sent in carrying drinking water, tents, tarpaulins, solar lights and other equipment to the civilians.

British Defense Secretary Philip Hammond said Britain was coordinating aid drops with the US and trying to help the refugees escape from "a completely unacceptable situation."

Meanwhile, French Foreign Minister Fabius arrived in Baghdad for talks on Sunday, and is due to fly to Irbil for further talks later in the day. He will also oversee the delivery of humanitarian supplies to civilians.

Thousands stranded

However, UNICEF's spokesman in Iraq Karim Elkorany told the Associated Press news agency the help was too late for some - and that dozens of children had already died of dehydration.

Hundreds of thousands of Iraqis have been forced to flee their homes, after IS militants have expanded their control across large sections of the country. Among them are Yazidis and people from other minorities, including the Shabak and Turkmen Shiites.

According to the United Nations, more than 500,000 people have been displaced by the violence in Iraq since June.

nm/ (AP, AFP, Reuters, dpa)