Ugandan police have discovered an unexploded suicide vest and have apprehended six individuals suspected of planning the bombings that killed 76 soccer fans. The attacks were carried out by Somali al Shabaab Islamists, who claimed responsibility for the bombings. A senior U.S. official confirmed the authenticity of al Shabaab's claim, marking the group's first attack outside of Somalia. U.S. President Barack Obama expressed sadness over the timing of the explosions during the World Cup final in South Africa. Obama spoke about two contrasting visions for Africa - one of progress and unity, and the other of destruction and death by groups like al Qaeda and Al Shabaab. The US government is working with Uganda and other regional governments to prevent future attacks by sharing intelligence and taking necessary measures. Despite receiving a tip-off about a possible attack, the US was not aware of any advance warning. According to a source in Uganda, an informant from the Kisenyi suburb of Kampala reported that there were plans for an attack during the World Cup by some Somalis. The source stated that more than 20 individuals, including Somalis and Ugandans, were involved in the planning of the attacks. As of now, six individuals have been arrested in connection with the plot. Al Shabaab has issued threats of further attacks unless Uganda and Burundi withdraw their peacekeepers from the African Union peacekeeping force in Somalia, where the militants are engaged in fighting the government and controlling significant portions of the country. Police discovered a suicide vest at a third location on Monday, which was designed to be planted rather than worn. A man claiming to be Yonis, assistant to al Shabaab spokesman Sheikh Ali Mohamud Rage, told Reuters that those who carried out the attack were blessed with rage and expected to live long lives, indicating that it was not a suicide bombing. Al Shabaab, in addition to banning alcohol, has also forbidden watching soccer matches in areas under its control. Coordinated attacks are a common tactic of al Qaeda and groups associated with Osama bin Laden's militant network. For al Shabaab, this would mark the first instance of the militants extending their quest for power beyond national borders. During an African Summit, U.S. Homeland Security Secretary Janet Napolitano expressed concern about the group's increasing reach, stating that they are now in a new phase of expansion. She emphasized the importance of enhancing preparedness, prevention, and interception measures to thwart potential terrorist attacks on U.S. soil. According to a U.S. official, al Shabaab has been closely monitored due to its connections with al Qaeda in East Africa and al Qaeda in the Arabian Peninsula. The official stated that the attack in Kampala was consistent with threats to expand their targets, but did not directly address whether the group posed a specific danger to the United States. Obama mentioned in an interview with the South African Broadcasting Corp that terrorist organizations do not value African life and see it as a place for ideological battles with no concern for the consequences. The African Union confirmed that Uganda would still host a summit of African leaders despite the attack, and the regional bloc IGAD vowed to continue supporting Somalia's government. IGAD also mentioned plans to increase peacekeepers in Somalia to over 8,000 by the second week of August. Last week, members of IGAD including Kenya, Uganda, Sudan, Ethiopia, Somalia, and Djibouti expressed their desire for 20,000 troops from the AU and United Nations to be deployed in Somalia. The opposition Forum for Democratic Change party in Uganda urged President Yoweri Museveni to withdraw his peacekeepers and stated that they planned to do so if they won the 2011 elections. The party's spokesman, Wafula Oguttu, told Reuters that there is no peace to maintain in Somalia and that Uganda has no strategic interest in the country. He said that Uganda is sacrificing its children without reason. Analysts believe that a sustained bombing campaign could harm Uganda's investment climate, but a single attack would likely not deter major companies like Tullow Oil from investing in the country. Foreign investment in the third largest economy in East Africa has increased significantly due to oil exploration along the western border with the Democratic Republic of Congo. One American citizen was killed in the incident, and five others were wounded and evacuated to Johannesburg and Nairobi. The U.S. State Department confirmed that an FBI team is currently in Kampala.