At least 26 people were killed and 18 wounded when a suicide bomber blew himself up in Kabul, Afghanistan on Wednesday, according an Interior Ministry spokesman. The explosion happened near a Shiite shrine in the west of Kabul, Reuters reported. The attack came as the city was celebrating the Nawruz holiday marking the start of the Persian new year. Earlier this month, General John Nicholson, the top US commander in Afghanistan, said security in Kabul would be “the main effort” for international powers helping Afghan defense and security forces. The extra security in the Afghan capital has turned the city center into a fortified zone, and security forces say they have intercepted numerous attacks before they took place.