most of saudi shiites live in the eastern province. that's also where the mostly the oil riches of the kingdom come from. the so-called islamic state isis has taken responsibility for the bombing. and this was the second bombing on a shiite mosque in saudi arabia in just over a week. >> well, all right this further exexpands on the thought that this is not just a land grab by i isis is. i mean, they are going into the shiite area of saudi arabia and this is, i mean, clearly sectarian war. the shiite vs. sunni. this is not a land grab in iraq. >> well, what's worrying is the broader context of why and where and what's happening. so beyond the tragedy of this one attack and the idea of the land grab and expansion. the context is worrying because shiites in the region are saying that this is a clear attempt by isis to ignite sectarian strife in the region and destabilize saudi arabia.