European airlines and Dubai-based Emirates Airline are rerouting flights over Iraq as a security precaution amid fears that militants with the Islamic State group have weapons capable of shooting down planes, despite Iraq saying its skies are safe. A number of European carriers, including Virgin Atlantic, KLM and Air France, said they had devised alternative flight plans for their planes. Air France detected a "potential threat" on July 24 which triggered the airline's decision, said Eric Prevot, a spokesman for Air France's flight operations centre. The decisions come after a Malaysia Airlines flight crashed over rebel-held territory in eastern Ukraine on July 17, killing all 298 people on board. US and Ukrainian officials say it was shot down by a missile from rebel territory, most likely by mistake. The Ukraine crash has many in the aviation industry reconsidering flight paths as hotspots from West Africa to Central Asia could potentially put passengers at risk. Though experts say the skies are largely safe, there is a danger of militants using sophisticated weapons. The Iraqi government also dismissed the fears, saying Iraqi skies and airports were safe. Iraq is facing its worst crisis since the 2011 withdrawal of US troops amid the blitz offensive launched last month by al-Qaeda breakaway group Islamic State, which captured large swathes of land in the country's west and north, including Iraq's second-largest city, Mosul. Many international commercial airlines said they were continuing to fly normally over militant-held areas in western and northern Iraq until recent days, when Dubai-based Emirates publicly announced it would avoid the regions. It had already been rerouting some flights before the announcement. Air France said it was currently avoiding numerous routes over Iraq, Syria and Libya, as well as eastern Ukraine and Crimea. Amsterdam-based KLM said it stopped flying over Iraq last week, adding that it had suspended some flights to Israel in recent days as a conflict between Israelis and Hamas in the Gaza Strip enters its fourth week. US airline Delta has no-fly zones over Afghanistan, Iran, Iraq, North Korea and Ukraine.