At least 74 people were killed and dozens injured in late night bombings targeting football fans in the Ugandan capital Kampala, with the Islamist al-Shaabab militia on Monday claiming responsibility for the attacks, according to dpa. Medical officials were concerned that the death toll could continue to rise as further victims were still fighting for their lives in hospital. The al-Shaabab militia in Somalia admitted to the bombings, which took place at venues where the World Cup final were being screened late Sunday. Spokesman for the group, Sheikh Ali Muhamed Rage, said: "Our fighters have implemented the explosions as intended in Kampala. "We have called the Ugandan people to give suggestions to their leaders to stop the massacres in Somalia, but they ignored our calls. We warn the Burundian people to withdraw their boys from Mogadishu or else they will face explosions in Bujumbura. "We will continue our attacks until they withdraw," he concluded, referring to the presence of African Union peacekeepers in Somalia. "I have heard that al-Shaabab elements were responsible for the attack," chief of police Kale Kayihura said late Monday. "But we have to concentrate on scientific methods to establish the facts." President Museveni, inspecting the two bombing sites, vowed to bring those responsible to justice. "We will find the perpetrators wherever they are and bring them to justice," he said. The government late Monday declared a week of mourning for the victims. In Mogadishu, Somalian President Sheikh Sharif Ahmed issued a statement calling the bombings a "reprehensible terror act." Police spoke of two bomb blasts, one in an Ethiopian restaurant and another at the Kyadondo Rugby Club where a crowd of football fans had gathered to watch the match between Spain and the Netherlands. But the Daily Monitor reported a possible third attack in the suburb of Ntinda. Many other restaurants and bars apparently closed out of fear of further attacks. At the rugby club, the bomb went off around 11 pm (2000 GMT), with the Daily Monitor newspaper reporting that at least 40 people were killed there. Blood, clothing, shoes and destroyed furniture littered the ground while security and medical personnel attended to the injured. At least 13 people were killed in the Ethiopian restaurant blast. Kayihura said that 14 foreign nationals were among the dead, including "nine Ethiopians and Eritreans, one American man, an Irish woman, one person of Asian origin and two unidentified expatriates." Privately-owned radio stations quoted unnamed officials as saying that the dead included an American, Phillip Henn, who had died of his injuries at Kampala International Hospital. KFM radio reported that another three Americans had sustained injuries. The German Foreign Office on Monday confirmed that one German man had been injured in the bombings. Somali extremists had threated attacks in Kampala because Ugandan troops are among the 5,000 African Union peacekeepers in Mogadishu. Somali troops are also being trained by the European Union in Uganda. The United States, which lists al-Shabaab as a terrorist group, condemned the attacks and noted that Americans might have been among those killed or injured. "I join President Obama in strongly condemning today's attacks in Kampala, Uganda, targeting innocent spectators watching the World Cup final," US Secretary of State Hillary Rodham Clinton said in a statement late Sunday. "We understand that American citizens may have been injured or killed, and our embassy is reaching out to assist," she said. "Our condolences go out to the families and friends of the victims in the United States and Uganda." The German government also condemned the bombings. "One can scarcely top the heinousness of attacking people while they are enjoying a peaceful festival of sport," Foreign Minister Guido Westerwelle said in a statement. "It shows the utterly inhuman despicableness of the people behind these attacks."