Museveni vowed to deal with troublemakers.
Uganda's President Yoweri Museveni has accused "external forces" of trying to foment trouble by funding his political opponents in a bid to undermine the country's image abroad.
In an hours-long televised speech late on Sunday, the 74-year-old railed against the opposition and accused "external forces" of seeking to "sabotage" Uganda's growth.
His address comes as Kampala grapples with a wave of unrest following the arrest of several parliamentarians including a former pop star, drawing an unusual amount of attention and condemnation from abroad.
Museveni, who took power in 1986, claimed "foreign money" was being funnelled to his political opponents by unnamed NGOs to foment trouble by paying youngsters to burn tyres and throw rocks at police.
The aim, he said, was to "show the world Uganda is not stable".
And Uganda would deal firmly with opposition troublemakers, he pledged.
"The indisciplined opposition politicians that are accused of terrorism against the population, conspiracy to commit arson or treason should be handled firmly," he said.
His remarks appeared to be directed at 34-year-old MP Robert Kyagulanyi, better known as pop star Bobi Wine, who entered parliament last year and has since become a lightning rod for youthful opposition to Museveni.
Kyagulanyi and more than 30 others were charged with treason after a crowd of opposition supporters allegedly threw stones at Museveni's motorcade, breaking a window.
Released on bail, the singer is in the US seeking medical treatment for injuries he claims were sustained while in custody.