Ugandan officials have charged 32 people with murder in connection with a July twin bombing attack that left scores dead in the capital, Kampala.
John Kagezi, the state attorney, said on Tuesday that four of those charged confessed to the July 11 attacks, in which 76 people were killed.
Hearings for the accused, which include Ugandan, Kenyan and Somali nationals, are expected to start on September 2.
No trial date has yet been announced.
Police, who charged three suspects in July with involvement in the attacks, have said that investigations are ongoing and that more arrests may follow.
The charges include 61 counts of murder for those killed in bomb blasts while watching the World Cup final on television at the Kyadondo Rugby Club in the east of the Ugandan capital and 15 counts for those killed at an Ethiopian restaurant.
Al-Shabab,a Somali group that is linked to al-Qaeda, has claimed responsibility for the two bombings.
Police had said there was "very strong evidence" that the attacks were carried out by suicide bombers.
The near-simultaneous attacks on Sunday were the first time the group, which has carried out multiple suicide attacks inside Somalia, has struck outside of the country.
Al-Shabab has said that it will continue to undertake strikes in Uganda and Burundi, in east-central Africa, for providing troops for the African Union (AU) peacekeeping force in war-torn Somalia.
However, African leaders have since approved a troop surge for the Somali force to counter the armed groups seeking to topple the embattled Somali government.
Jean Ping, the AU commission chief, said they had received pledges for 4,000 troops to beef up the force which currently comprises some 6,000 Ugandan and Burundian soldiers.
However, some observers argue that more troops risk worsening the near-daily violence in Mogadishu, the Somali capital, and buttressing the rebels' cause.