the terror group affiliate known as isis-k is taking response for the deadly explosion outside a mosque in the afghan capital. they are not revealing details but say a number of people were killed in sunday s blast. it happened during a funeral service for the mother of a taliban spokesman. clarissa ward is in kabul for us. i assume this is a test of the taliban s ability to keep control. what are you seeing, and what are they saying? well, alisyn, this is definitely significant. it s the largest attack that we ve seen here in the capital since that horrific bombing at the airport. ministry of interior sources telling cnn that seven people