The bombs exploded in an Ethiopian restaurant and a rugby club in the capital Kampala, killing 64 and injuring dozens of football fans that had gathered to watch the World Cup final.

"This tragic loss of life is completely inexcusable and we condemn it whole-heartedly," said Michelle Kagari, Deputy Africa Director at Amnesty International.

An al-Shabab commander has reportedly condoned the blasts while refusing to comment on whether the group was responsible.

Ugandan soldiers form part of the African Union peacekeeping force that is assisting the Somali government in its struggle against al-Shabab and other militant groups in the country.

"It is now essential that the Ugandan police conduct their investigation into the attacks in line with international standards to ensure the perpetrators are brought to justice," said Michelle Kagari.