BBC Online :The US has carried out its first air strike against Islamic State (IS) militants under a new strategy to defeat the group.The US military said Monday’s strike had destroyed an IS fighting position south-west of Baghdad that had been firing on Iraqi forces.It came five days after US President Barack Obama outlined his plan to “degrade and ultimately destroy” IS.The US has also been building a broad coalition to fight the jihadist group.IS, also known as Isil or Isis, has announced the creation of a caliphate, or Islamic state, in the large parts of Syria and Iraq it controls.”The air strike south-west of Baghdad was the first taken as part of our expanded efforts beyond protecting our own people and humanitarian missions to hit Isil targets as Iraqi forces go on offence, as outlined in the president’s speech last Wednesday,” US Central Command said.It did not specify the exact location but Iraqi security spokesman Lt Gen Qassem Atta told AFP news agency it was “an important strike” in Sadr al-Yusufiya, 25km (15 miles) from the capital.The US also said an IS position near the north-western town of Sinjar had been targeted on Sunday, destroying six IS vehicles.US fighter planes have conducted more than 160 airstrikes across Iraq since August.Previous US air strikes in Iraq have been carried out to protect US interests and personnel, help Iraqi refugees and secure infrastructure.In a speech last week, President Obama unveiled a four-point plan to defeat IS using air strikes, material and technical support for Iraqi ground troops, counter-terrorism activities and humanitarian help.He has said there are no plans to send in US ground troops.However, the former commander of UK forces in Afghanistan, Col Richard Kemp, told the BBC on Tuesday that if the current strategy failed, ground troops from the coalition may be inevitable.”If this threat is serious enough to warrant air strikes against it, and ultimately the strategy of using local forces on the ground doesn’t work, then it must be serious enough to deploy our own forces,” he said.In another development on Tuesday, IS fighters are reported to have shot down a Syrian warplane over their northern stronghold of Raqa.The Syrian Observatory for Human Rights, a UK-based group that monitors the conflict, said it was the first Syrian jet shot down since the government launched air strikes against the jihadists in July.Meanwhile, Iraq has criticised the decision not to invite Iran to Monday’s Paris summit on the IS threat.Thirty countries pledged to join a US-led coalition against IS at the talks.Iraqi Foreign Minister Ibrahim al-Jaafari said the decision not to include Iran was “regrettable”.”We believe that all world countries are concerned about the danger of terrorism,” he said.”Iran is our neighbour, it assisted us and it should have been present, but we are not the party responsible for inviting parties,” he added.