WASHINGTON - The Islamist militant attack on a Kenyan shopping mall increasingly appears to have been carried out by a dominant faction of al Shabaab, which has ideological and personal ties to al-Qaida, US officials said on Thursday.
Based on initial reporting from the scene, which is still preliminary and uncertain, US officials believe al Shabaab likely spent a great deal of time planning and staging the siege in Nairobi that killed at least 72 people.
Officials say, for example, the Islamist militants may have moved a large machine gun and supplies of ammunition into place somewhere inside the mall days or weeks before the attack - perhaps by renting a shop or secretly using space provided by a sympathetic shop owner or employee.
The attack has highlighted the reach of al Shabaab and its sharpening focus on targets outside of Somalia, the officials said.
US officials say they don't believe Shabaab currently presents a threat to the US mainland but does threaten U.S. interests in countries near Somalia.