ARBIL - US warplanes bombed jihadist positions in northern Iraq on Friday, in what the federal and Kurdish governments vowed would allow them to start clawing back areas lost in two months of conflict.
President Barack Obama's order for the first air strikes on Iraq since he put an end to US occupation in 2011 came after Islamic State (IS) militants made massive gains on the ground, seizing a dam and forcing a mass exodus of religious minorities.
The Pentagon said US forces bombed an artillery position after fire against Kurdish regional government forces defending their capital Arbil.
In a second wave hours later, a drone destroyed a mortar position and jets hit a seven-vehicle IS convoy with eight laser-guided bombs.
The US operation began with air drops of food and water for thousands of people hiding from the Sunni extremist militants in a barren northern mountain range.
Many people who have been cowering in the Sinjar mountains for five days in searing heat and with no supplies are Yazidis, a minority that follows a 4,000-year-oldfaith.
Late Friday the Pentagon said that cargo planes escorted by combat jets made a second air drop of food and water to "thousands of Iraqi citizens" threatened by the jihadists "on Mount Sinjar, Iraq."
Obama accused the IS, which calls Yazidis "devil-worshippers", of attempting" the systematic destruction of the entire people, which would constitute genocide".
The UN said it was "urgently preparing a humanitarian corridor".
Panic had begun to grip Arbil after IS thrust into the Nineveh plains separating it from the jihadist-held city of Mosul and Obama's decision was welcomed there.