At least three people have been killed and seven injured in an explosion at a hotel in <a href="https://www.thenationalnews.com/tags/afghanistan" target="_blank">Afghanistan</a>'s south-eastern Khost province. Residents of Khost and Waziri refugees were among those killed on Monday, Kabul police spokesman Khalid Zadran wrote on social media platform X, formerly known as Twitter. The explosion took place about 11am, he said. An investigation was continuing into the nature of the blast. Khost is the largest city in Afghanistan's south-east, lying on the border with Pakistan. It is rife with militant attacks and houses a number of refugees from Pakistan's Waziristan. Pakistan, where militant attacks are spilling over from Afghanistan, has complained the Taliban are not doing enough to fight armed groups. The Taliban say they have been cracking down on ISIS cells in the country. It was not immediately clear who was behind Monday's<b> </b>incident. The blast happened a day before the two-year anniversary of the Taliban's return to power. More than 1,000 Afghan civilians have been killed in bombings and other acts of violence since the <a href="https://www.thenationalnews.com/tags/taliban/" target="_blank">Taliban</a> took over the capital Kabul in 2021, the <a href="https://www.thenationalnews.com/tags/un/" target="_blank">UN</a> mission to Afghanistan said in a June report. Most of the deaths were caused by improvised explosives in areas near mosques and markets. Afghanistan continues to face security challenges, particularly from <a href="https://www.thenationalnews.com/tags/isis/" target="_blank">ISIS</a>. The UN has said the terrorist group is responsible for most of the attacks.