There is a “very credible” threat of a “highly lethal” terror attack on the Kabul airport within hours, a UK minister has warned. Britain’s armed forces minister James Heappey said on Thursday that there is “very credible reporting” of an “imminent” and “severe” threat to the airport from the ISIS terrorist group. The U.S. Embassy in Kabul issued an alert on Wednesday evening, urging citizens to avoid traveling to the airport and said those already at the gates should leave immediately, citing unspecified “security threats.” Britain and Australia have also urged their citizens and visa holders not to travel to the airport, where thousands are waiting to be evacuated out of the country ahead of the Aug. 31 deadline. The British government now believes there is a “very imminent” risk of a “highly lethal” attack possibly within Kabul, Heappey told “BBC Breakfast.” “As a consequence, we’ve had to change the …