The Somali Islamist group al-Shabab has said it was behind twin blasts which hit the Ugandan capital Kampala on Sunday, killing 74 people.
A spokesman for the group, Sheikh Ali Mohamud Rage, threatened more attacks in a statement in Mogadishu.
Police said the bombings targeted football fans watching the World Cup final.
A Ugandan official said a Somali’s head was found at the scene of one blast, and he may have been a suicide bomber.
Ugandan peacekeepers are in Somalia, and al-Shabab has previously threatened Kampala.
“Al-Shabab was behind the two bomb blasts in Uganda,” Ali Mohamud Rage said.
“We thank the mujahideen that carried out the attack. We are sending a message to Uganda and Burundi, if they do not take out their Amisom [African Union Mission in Somalia] troops from Somalia, blasts will continue and it will happen in Bujumbura [the Burundi capital] too.”
The explosions, which also injured about 70 people, ripped through a rugby club and an Ethiopian restaurant as football fans watched the last few minutes of the World Cup final.
Foreigners killed the deadliest of the blasts was at the crowded rugby club. At both locations chairs lay overturned, with blood and pieces of flesh on the floor.
A government spokesman said on Monday that at least 28 Ugandans were killed in the explosions.
Fred Opolot, quoted by the Reuters news agency, said an Irish woman was among those who died at the restaurant.
Officials said the dead and wounded also included Ethiopian, Eritrean, Indian and Congolese nationals.
Mr Opolot added that the other victims had not yet been identified.
Aware of threatUgandan Internal Affairs Minister Matia Kasaija told the BBC World Today programme that the severed head of a person from Somalia had been identified at the scene of one blast.
I just remember running and stepping over the bodies that had blood spilling from their bodies
He said Uganda had been aware of the threat, but had been caught off-guard.
About 5,000 African Union troops from Uganda and Burundi are based in Mogadishu, propping up the fragile interim government.
The Amisom force is engaged in frequent firefights with the Islamist insurgents that control much of southern and central Somalia.
American dead the attack on the Ethiopian restaurant also fits in with al-Shabab’s regional policy.
Addis Ababa backs Somalia’s government against the rebels. And Ethiopian troops invaded Somalia in 2006 to oust an Islamist movement, stoking an insurgency that still rages.
BBC East Africa correspondent Peter Greste says security services across the region will now be reassessing how they can protect themselves from a force that has proven itself willing and capable of striking outside Somalia’s borders.
Many – if not most – of those killed and injured in the Kampala blasts were foreign nationals. Both venues are popular destinations for expatriates living in the capital.
One unnamed witness told the BBC how he was caught in the rugby club blast.
“I just heard the bomb. In fact, I blacked out… when I gained consciousness, then I started now, crawling, coming out,” he said.
California-based aid group Invisible Children, which helps child soldiers, said one of its workers, Nate Henn, 25, was among those killed at the rugby club.
At least three Americans, members of a Church group from Pennsylvania, were wounded at the Ethiopian restaurant.
One, Kris Sledge, 18, of Selinsgrove, Pennsylvania, said from his hospital bed: “I remember blacking out, hearing people screaming and running.”
Ugandan President Yoweri Museveni criticised the attackers and said his country would not “run away” from its commitments in Mogadishu.
“People who are watching football are not people who should be targeted. If they [attackers] want a fight, they should go and look for soldiers.”
US President Barack Obama said the explosions were “deplorable and cowardly”.
The African Union has said the attacks will not affect its summit, which is due to be held in Kampala later this month.
Ethiopian troops invaded Somalia in 2006 to oust an Islamist movement from Mogadishu. That sparked the Islamist insurgency which still rages.
Uganda, east Africa’s third largest economy, is attracting billions of dollars of foreign investment, especially in its oil sector and government debt markets.
But investors in Uganda and neighboring Kenya, which shares a largely porous border with Somalia, often cite the threat from Islamic militants as a serious concern.
“I certainly think the blasts will make risk appraisals tighter on Uganda. If it does transpire to be al Shabaab that will certainly raise the concerns of Western investors and also Chinese investors in Uganda,” said Alex Vines, Head of Africa Programs at London’s Chatham House think-tank.
The Ugandan shilling fell slightly against the dollar on Monday after the blasts.
What does this all mean ?
This attack is the first instance of targeting civilians by association with AMISOM (African Union peace force). I note that one of the venues was an Ethiopian restaurant in Kampala. I expect it to increase anxiety about al Shabaab and the situation in Somalia both in the region and in the international community more widely. It might hasten the process of extending participation in AMISOM to include neighbouring states (who are currently barred.).
Uganda was probably a soft target. Good intelligence is how you stop terrorist attacks and that is often going to be weaker in Africa. As to who was behind it, I think you’ll find the murky fingers of AQ somewhere in there.
A sustained bombing campaign would be bad, but again I think investors would adapt.
We know al Shabaab tried an attack in Kenya in 2009 so another external attack was always likely. The targeting of an Ethiopian restaurant full of foreigners also reinforces this idea – 3 targets in 1 really – Ethiopia, Uganda and the U.S. The regional security question …I am not sure at this stage. I think an attack in Kenya/Djibouti would likely have greater repercussions than Uganda, where there is less U.S. presence to worry about. For example, a large attack on Americans in Djibouti would probably prompt a much bigger response due to that country’s military strategic importance.
This will certainly trigger a greater call for tougher action on terrorism in Uganda and the region. The most likely response will be to increase Uganda’s role in Somalia and that will have consequences. If they use more robust force in a controlled manner, that is likely to help TFG in Somalia by weakening of al Shabaab.
Here is President Museveni telling Al-Shabab to lay down from last fall.
The U.S government intelligence has warned that Al-Shabab is recruiting Kenyans to assist in carrying out terrorist attacks for a while.
In Washington, U.S. National Security Council spokesman Mike Hammer said Obama was “deeply saddened by the loss of life resulting from these deplorable and cowardly attacks.”
“The United States is ready to provide any assistance requested by the Ugandan government,” said Hammer.
In depth discussion here.