Obama administration officials again are emphasizing the threat they say al-Qaida and related groups such as al-Shabab pose in Africa, after the recent deadly attacks in Uganda.
White House Press Secretary Robert Gibbs, in a briefing with reporters, echoed earlier administration comments that Islamist extremist groups have no respect for people in Africa.
"I think they have taken steps to prey on Africans, and they do not value the continent or its people," said Robert Gibbs.
The Somali militant group al-Shabab says it was responsible for two bombings that killed more than 70 people watching the recent World Cup final on television in Kampala, Uganda. Al-Shabab is linked to the al-Qaida terror network.
Earlier this week, a senior White House official called al-Qaida "a racist organization that treats black Africans like cannon fodder and does not value human life."
U.S. President Barack Obama says the attacks show that extremist groups have no regard for African lives.
In an interview with the South African Broadcasting Corporation this week, Mr. Obama said terrorists do not consider the long-term consequences of killing innocent people.
"On the one hand, you have a vision of an Africa on the move, an Africa that is unified, an Africa that is modernizing and creating opportunities," said President Obama. "And on the other hand, you have got a vision of al-Qaida and al-Shabab that is about destruction and death."
Mr. Obama said this week's attacks show that al-Shabab and other terror groups must be stopped.
"If al-Shabab takes more and more control within Somalia, it is going to be exporting violence the way it just did in Uganda," said Mr. Obama.
U.S. security officials say this is the first time that al-Shabab has carried out attacks outside Somalia. They say the United States is helping the Ugandan government investigate the bombings, and that it is offering support to other countries in the region to prevent other attacks.