US and allied aircraft have flown nearly 6,600 sorties in the air war against Islamic State and dropped more than 1,700 bombs, the American military said on Thursday. The flights for “Operation Inherent Resolve” include thousands of mid-air fuelling runs, surveillance sorties and 632 air strikes in Iraq and Syria, according to US Central Command. The latest tally was released one month after the US-led coalition extended its air campaign from Iraq into Syria, in a bid to counter the advance of the Islamic State jihadists. The effect of the open-ended air campaign remains the subject of debate, with the White House saying the militants have been damaged by the strikes and critics pointing to the group’s battlefield successes despite the raids. Coalition aircraft have targeted Islamic State militants with more than 1,700 bombs and missiles since August 8 in both Iraq and Syria, Central Command said in a statement. Washington often stresses that a broad coalition is fighting the Islamic State militants, but US aircraft have conducted the overwhelming majority of the strikes so far. Out of 632 bombing raids, non-US coalition members – including four Arab states – carried out only 79 of the strikes, Central Command said. In Iraq, aircraft from Australia, Belgium, Britain, and the Netherlands have taken part in the strikes along with the United States. And in Syria, the Americans have been joined by combat aircraft from Bahrain, Jordan, Saudi Arabia and the United Arab Emirates, it said. The Central Command statement did not cite Qatar as conducting air strikes, but officials say the country has “supported” the operation with other assistance. Details about the flights and missions undertaken by Arab allies have been kept secret for the most part, with the Gulf countries reluctant to publicly discuss their role. In its daily press releases on the air campaign, Central Command this week said it would stop providing details of which Arab states participated in the latest air strikes, without offering an explanation for the move. A little more than half the strikes – 346 – have taken place in Iraq, while 286 were conducted in Syria, it said. The American warplanes flying bombing missions have included Reaper drones, F-15, F-16, F/A-18 and F-22 fighter jets, B-1B bombers, Harrier strike aircraft and AC-130 gunships, which are modified cargo planes outfitted with powerful guns. In addition, AH-64 Apache attack helicopters have carried out at least two strikes in Iraq on October 4 and 5, it said. Most of the aircraft fly from bases in the region, including airfields in Kuwait, the United Arab Emirates and Qatar. But Washington and its Arab allies have declined to discuss which bases are being used and which planes are flying of out of them.