Jordan's national carrier on Saturday suspended flights to the Iraqi capital for security reasons, an airline official told AFP.
"Royal Jordanian suspended its flights to Baghdad today because of the security situation," said the source, speaking on condition of anonymity.
The airline was closely monitoring developments in Iraq and may extend the suspension of flights, added the source.
Islamic State fighters killed 16 Kurdish troops in attacks in northern Iraq, while 30 pro-government forces died in clashes with the jihadists on other frontlines, Iraqi officials said on Saturday.
The jihadist group, which has already seized large swathes of Syria, launched a blistering offensive on June 9 that saw them capture Mosul, Iraq's second city, and move into much of the country's Sunni heartland.
Royal Jordanian has 30 scheduled flights a week to Iraq, mainly to Baghdad and also to Arbil, capital of the autonomous Kurdish region in the north.
On Friday, Germany's Lufthansa said it was halting flights over Iraq until late Sunday.
Australian carrier Qantas also said Saturday it was suspending flights over the conflict zone despite earlier pledging to carry on.
Air France-KLM, Delta, Emirates, United and Virgin Atlantic had previously said they had stopped flying through Iraqi airspace.
The shooting down over rebel-held territory in Ukraine last month of a Malaysian airliner by a ground-to-air missile brutally highlighted the dangers of civilian aircraft overflying combat zones.
But British Airways said on Saturday it would keep flying over Iraq, despite the downing of Flight MH17 in Ukraine.
Abu Dhabi's Etihad Airways has also said it will continue to use the flight path over Iraq.