KABUL: A busload of Nepali security guards were among 23 people killed in a string of bombings across Afghanistan on Monday, days after Washington expanded the US military’s authority to strike the Taliban. A Taliban spokesman on Twitter claimed the first attack, which killed 14 Nepali security guards working for the Canadian Embassy in Kabul in a massive blast that left their yellow minibus spattered with blood. However Islamic State’s affiliate in Afghanistan and Pakistan released a competing claim in which they named and pictured the alleged bomber, according to the SITE monitoring group, in what would be their most significant attack in the country. An Afghan intelligence source said officials were investigating the IS claim, which was flatly denied by the Taliban. The Taliban also claimed a second, smaller blast in south Kabul on Monday that the interior ministry said killed one person. The bombings were followed hours later by an attack on a market in the remote northeastern province of Badakhshan that authorities said killed at least eight people, with the death toll set to rise. The wave of violence comes 10 days after Washington announced an expansion of the US military’s authority to conduct air strikes against the Taliban, a significant boost for Afghan forces who have limited close air-support capacities. The Canadian Embassy in Afghanistan confirmed the “cowardly” attack in a tweet, and said that it had employed the guards.