What we know about Iranian attack on a US base in Qatar

Iran has launched missiles at a US military base in Qatar, in what it said was retaliation for American strikes against its nuclear sites over the weekend. Witnesses have reported hearing loud bangs in the sky above the capital, Doha, while videos show bright flashes in the sky as air defence systems attempt to intercept missiles. It is the latest escalation in a conflict involving Iran, Israel and the US which has seen tensions in the Middle East soar to unprecedented levels in recent days. Details of this latest attack are still emerging. Here is what we know so far. Iranian missiles targeted the largest US military base in the Middle East, Al Udeid Air Base. About 8,000 US citizens are based there, according to the State Department, and it is home to US military's headquarters for all its air operations in the region. Some British military personnel also serve at the base on rotation. The Qatari government said no one had been killed or injured in the attack, and that the base had been evacuated beforehand. It is unclear whether any of the missiles hit the base, or if there has been material damage. The attack was first confirmed by Iranian state media, and later by the military. A statement from the IRGC, the most powerful branch of the Iranian military, said that "Iran will not leave any attack on its sovereignty unanswered", and added: "US bases in the region are not strengths but vulnerabilities." The US had previously warned Iran not to respond to its strikes on nuclear facilities and urged leaders in Tehran to agree to a diplomatic end to hostilities in the region. The White House is yet to respond to the latest attack. There were indications on Monday that the US suspected Iran was preparing to launch missiles into Qatar. Hours before the attack, Qatar said it was temporarily closing its airspace. That came shortly after the US and UK told their nationals in the country to take shelter until further notice. Those warnings did not give a clear indication an attack was imminent: the US said it issued the order "out of an abundance of caution", while the UK said it was following the lead of the Americans. However, around an hour before the attack, the BBC learned of "a credible threat" to the base. Separately, some US media outlets quoted anonymous US officials as saying Iranian missile launchers had been positioned for a potential launch towards Qatar. Flight tracking websites showed planes had already started diverting to other airports ahead of the launch. According to Flightradar24, there were 100 flights bound for Doha shortly before missiles were detected. Hamad International Airport is one of the world's top 10 busiest for international traffic, with around 140,000 passengers passing through per day. Other countries in the region, including Bahrain and Kuwait, also closed their airspaces. Overnight on Saturday, the US launched massive strikes against three nuclear facilities inside Iran. That came after days of uncertainty over whether the US would join Israel's military action against Iran, which started on 13 June. Israel has been launching daily missile strikes against nuclear and military facilities inside Iran, which its government says are necessary to prevent Iran from imminently building a nuclear weapon. Successive Israeli and American governments have sought to prevent Iran from acquiring a nuclear weapon. Iran has always maintained its extensive nuclear programme is for civilian purposes. The US claimed its strikes badly damaged Iran's nuclear programme, though the full extent of their impact remains unclear. Strikes between Iran and Israel also continued on Monday.