Somali al Shabaab Islamists linked to Al-Qaeda said on Monday they had carried out the attacks on a crowded restaurant and a rugby club in the capital Uganda while fans watched the World Cup final on television.

An official from the group said on Tuesday there had been no suicide bombers involved in the attack on Uganda, which has peacekeepers in Somalia.

A Ugandan military intelligence source told Reuters on Tuesday that intelligence officials had received a tip-off last month that an attack was being planned.

"On June 17 an informer from the Kisenyi suburb of Kampala told intelligence that some Somalis were planning an attack during the World Cup," the source said.

The official said more than 20 people, Somalis and Ugandans, were involved in planning the attacks. "So far we have arrested six people from that racket," he said.

Al Shabaab has threatened more attacks unless Uganda and Burundi withdraw their peacekeepers from the African Union (AU) peacekeeping force in Somalia (AMISOM), where the militants are fighting the government and control large parts of the country.

Police said the suicide vest found late on Monday at a third site was designed so it could also be planted, rather than worn.

"Rage blessed those who carried the attack and expected a long life for them. That shows there was no suicide bomb. These were planted," a man who identified himself as Yonis, assistant to al Shabaab spokesman Sheikh Ali Mohamud Rage, told Reuters.

As well as banning alcohol, al Shabaab has banned watching soccer matches in areas under its control.

Coordinated attacks are a hallmark of Al-Qaeda and groups linked to Osama Bin Laden's militant network.
 

"I think that there's a common recognition that this is a new phase for al Shabaab in terms of expanding their geographic reach unfortunately," US Homeland Security Secretary Janet Napolitano told reporters.

"We are constantly looking at ways that we can increase our preparation for, prevention of, and interdiction of any type of terrorist attack before it should occur on our own soil."

The African Union said Uganda would still host a summit of African leaders this month and said it would not be deterred from its peacekeeping mission.

"The government of Uganda added there will be no danger to visiting heads of state and dignitaries ... The AU summit will not be disturbed by this incident," Noureddine Mezni, spokesperson for AU commission chairman Jean Ping told Reuters.

Regional bloc IGAD also said it would not be cowed and would continue to support the Western-backed government in Somalia.

"We shall continue with our plans to increase peacekeepers in Somalia to over 8,000 and we hope to have the extra troops in the country by the second week of August," executive secretary Mahboud Maalim told journalists in the Kenyan capital Nairobi.

Last week IGAD members Kenya, Uganda, Sudan, Ethiopia, Somalia and Djibouti said they eventually wanted 20,000 troops from the AU and United Nations deployed in Somalia.

Uganda's opposition Forum for Democratic Change (FDC) party urged President Yoweri Museveni to pull his peacekeepers out and said it planned a withdrawal if it won elections in 2011.

"There is no peace to keep in Somalia and Uganda has no strategic interest there. We're just sacrificing our children for nothing," FDC spokesman Wafula Oguttu told Reuters.

Analysts say any sustained bombing campaign would damage Uganda's investment climate, but a one-off attack was unlikely to deter major companies such as British hydrocarbons explorer Tullow Oil from investing.

Foreign direct investment into east Africa's third largest economy has surged, driven by oil exploration along the western border with Democratic Republic of Congo.

One American was among the dead. The US embassy in South Africa said five other US citizens who had been wounded had been evacuated to Johannesburg and Nairobi. An FBI team is in Kampala, the US State Department said.
 

An intelligence assessment by the FBI and the US Homeland Security Department said Tuesday that iIf the Al-Shabab is responsible for the deadly attacks in Uganda, it could mean the group is capable of carrying out successful attacks in Africa and beyond.

This attack would be Al-Shabab's first successful strike outside of Somalia, according to the July 12 intelligence analysis obtained by The Associated Press. The document is marked for official use only and was distributed to law enforcement officials across the country. US officials have yet to publicly comment on the significance of the attacks.

Intelligence officials have previously considered the Al-Qaeda affiliated group a threat to the US In 2007 and 2008, about 20 Somali-American men were recruited and left the Minneapolis area to join forces with Al-Shabab.

And Omar Hammami, a US citizen currently based in Somalia, has appeared in the terror group's media productions and urged people to travel to Somalia for terror training, according to a May 21 Homeland Security intelligence assessment about the evolution of terror threats to the US

"We cannot exclude the possibility that US persons aligned with Al-Shabab in the Horn of Africa may return to the US, possibly to carry out acts of violence," said the assessment, also obtained by The AP.

Shortly before President Barack Obama's inauguration, US officials were concerned about intelligence they received regarding a potential threat from Al-Shabab to the event.

By the time Obama was sworn in, the threat had been debunked.

Al-Shabab, which means "The Youth," has been gaining ground as Somalia's Western-backed government crumbles. The group's goal is to establish an Islamic state in Somalia.

The FBI's New York office and the New York Police Department said Tuesday that a team of investigators, including forensic experts, from the city's Joint Terrorism Task Force was en route to Uganda to assist authorities there with the probe.
 
— With an Associated Press report