Suicide bombers conducted two near-simultaneous attacks Aug. 26 near the entrance to Kabul's Hamid Karzai International Airport, Yahoo News reported. One bomber detonated an explosive vest in a crowd gathered outside the Abbey Gate entrance to the facility, while a second bomber conducted a nearby attack outside the Baron Hotel, which houses British nationals awaiting evacuation. There are unconfirmed reports that another militant opened fire outside the airport gate immediately following the first explosion there, further suggesting a coordinated attack. Taken together, the incidents have killed at least 13 people thus far — including reportedly four U.S. Marines, along with civilians and Taliban guards — and wounded at least 60 people, but the casualty toll will likely rise. U.K. officials stated that there were no British casualties in the attack, but other nations have not provided updates. Local reports indicate the Islamic State in Khorasan Province (ISKP) claimed responsibility for the attack on Telegram.

The purported ISKP attack follows Aug. 25 messages from the U.S. Embassy in Kabul and the British Foreign Office warning their citizens to avoid the Abbey Gate, suggesting specific, detailed intelligence about an impending attack targeting evacuation operations at the airport. The attack came as the United States and other countries scramble to meet an Aug. 31 deadline to evacuate their citizens, government personnel and Afghans who worked with NATO forces. There are unconfirmed reports that Taliban officials provided intelligence to U.S. officials prior to the suicide bombings, but U.S. officials have not commented on those reports. The Taliban and ISKP have a significant rivalry and the groups have routinely fought each other as the Taliban has sought to distance itself from terrorist groups.

The attack highlights the persistent terrorist threat in Afghanistan from ISKP, which has launched similar high-profile bombings in Kabul, and portends short- and long-term security risks. In the short term, there is a significantly heightened risk of further attacks aimed at evacuation operations in and around the airport, as well as ISKP attacks in other areas of Afghanistan that have received less attention from media and security services. In combination with the risk of further attacks, there is a possibility that the Aug. 26 suicide bombings will delay evacuation operations beyond the Aug. 31 deadline, which could lead to renewed hostilities between the Taliban and foreign forces in the country. This would be particularly likely if the United States retaliates for the Aug. 26 attack, which is likely following the deaths of U.S. personnel. Such retaliation could prompt further ISKP attacks and possibly endanger U.S. relations with the Taliban in the event the group views ongoing U.S. military operations in the country as a breach of their agreement for foreign forces to withdraw, especially if U.S. retaliation were also to hit Taliban, not just ISKP, targets.

Regardless of the immediate fallout and security risks from the Aug. 26 attack, the suicide bombings highlight the persistent risk of terrorism emanating from Afghanistan — a major concern cited by those who oppose the withdrawal of foreign troops — which will pose a significant threat not only to countries in the surrounding region, but also possibly to the West. While ISKP has primarily conducted attacks in Afghanistan and Pakistan, Western officials have publicly aired concerns that the group has demonstrated an interest in conducting external operations that could pose a more acute threat to Western interests and individuals. Additionally, the broader Islamic State movement continues to inspire radicalized individuals to conduct attacks across the globe, including in the West, and the Aug. 26 suicide bombings could motivate sympathetic followers to plot follow-on attacks. While these are more likely to be small-scale attacks involving readily available weapons like knives rather than coordinated bombings, the threat of future attacks by globally dispersed Islamic State followers will remain — and could grow if ISKP takes advantage of the withdrawal of foreign forces to exploit a potential haven in Afghanistan.