At least 64 people, including one American, have been killed in bomb blasts at two bars in Uganda's capital as people watched the World Cup final on TV.
Police Chief Kale Kaihura said he believed that Somalia's most feared militia, al-Shabab, could be behind the attacks.
The organisation has pledged loyalty to al Qaeda.
The president is deeply saddened by the loss of life resulting from these deplorable and cowardly attacks, and sends his condolences to the people of Uganda and the loved ones of those who have been killed or injured.White House spokesman Tommy Vietor
The second blast went off at a bar called the Kyadondo Rugby Club.
Kaihura said 14 people were killed at the Ethiopian bar and many more at the Rugby Club.
If the police chief's early suspicions that al-Shabab was responsible prove true, it will be the first time the group has carried out attacks outside of Somalia.
One of the injured is carried for treatment
after an attack in the capital
But he refused to confirm or deny that al-Shabab was responsible for the bombings.
"Uganda is one of our enemies. Whatever makes them cry, makes us happy. May Allah's anger be upon those who are against us," Issa said.
White House spokesman Tommy Vietor said America is prepared to provide any necessary assistance to the Ugandan government.
"The president is deeply saddened by the loss of life resulting from these deplorable and cowardly attacks, and sends his condolences to the people of Uganda and the loved ones of those who have been killed or injured," he said.