Kampala: Uganda heightened its "terror" alert to maximum on Friday for the first time since bombings in 2010 that killed 79 people, given domestic and US intelligence indications of a possibly imminent attack by Islamist militants, a police spokesman said.
Uganda recalled security staff from leave and deployed thousands of extra police across the capital Kampala after raising the alert level to red, Patrick Onyango told Reuters.
"Our intelligence and that of the Americans show that an imminent terror attack is likely," Onyango said.
Uganda had already heightened security after at least 67 people were killed in an attack on a shopping mall in the Kenyan capital Nairobi claimed by the Somali militant group al Shabaab.
Al Shabaab also carried out the 2010 bombings in Kampala, targeting crowds gathered for the occasion of the soccer World Cup final in reprisal for Uganda's participation in an African Union force that swept into Somalia to neutralise Islamist rebels and help end prolonged war and anarchy in the country.
Al Shabaab attacked the Westgate mall in Nairobi also in retaliation for Kenyan military intervention in Somalia.
The U.S. Embassy in Kampala said on Tuesday it was assessing reports that a "Westgate-style attack may soon occur in Kampala". It also cautioned its citizens to be vigilant about visiting crowded areas.
Onyango appealed for citizens to be understanding as police carry out more random searches and said the force's staff would not be allowed to take leave until further notice.
Al Shabaab has issued several threats to again strike Uganda, a staunch western ally, unless it withdraws from Somalia where its troops are fighting against Islamists as part of a 17,000-strong AU peacekeeping force.