Not specified in the actual alert, but putting two-and-two together, via AFP:
The US embassy gave no further specific information on the threat, but the east African nation – a trusted US ally – has been attacked in the past by Somalia’s Al-Qaeda-linked Shebab militants.
Uganda is a key contributor to the African Union’s AMISOM force battling the Shebab inside Somalia.
In 2010 the Islamists carried out twin bombings in Kampala targeting a restaurant and a club where football fans were watching the World Cup final between the Netherlands and Spain, killing 76 people in the region’s worst attacks in more than a decade.
The US embassy in Kampala last issued an emergency warning in September 2014. Ugandan and Western security sources later revealed they had intercepted a transfer of explosive suicide vests by suspected Shebab members and made 19 arrests.