Ugandan police have found an unexploded suicide vest and made a number of arrests after coordinated bomb blasts ripped through two bars and killed at least 76 soccer fans watching the World Cup final on Sunday.

The twin explosions ripped through two bars heaving with soccer fans watching the closing moments of the World Cup final on television late on Sunday.

"Arrests were made late yesterday after an unexploded suicide bomber's belt was found in the Makindye area (of the capital Kampala)," said government spokesman Fred Opolot.

He did not say how many people were arrested after the attacks, for which an armed Somali group, al Shabaab claimed responsibility. Al Shabaab have threatened further attacks on Uganda and Burundi, both of which have soldiers as Africa Union peacekeepers in the Horn of Africa nation, if the troops are not withdrawn.

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.

The vest was found on Monday in Makindye, a suburb of Kampala, and was consistent with evidence found at the other blast sites in the capital, Inspector General of Police Kale Kayihura told reporters.

Ugandan police said the vest was designed so it could be planted, rather than worn, and be used as an improvised bomb.

Opolot said there was no suggestion an African Union summit to be hosted by Uganda later this month would be cancelled following the bombings.

Reuters