In a social media post on Sunday, Ugandan President Yoweri Museveni's son, Muhoozi Kainerugaba, who is head of the army, said there were "some issues" with the current German ambassador to Uganda, Matthias Schauer, branding him "wholly unqualified".

That came after Schauer was singled out for criticism by the Ugandan army, which accused some European embassies of supporting "negative and traitorous groups" in a statement.

"The allegations on the part of the Ugandan military are absurd and have no basis whatsoever," German foreign ministry spokeswoman Kathrin Deschauer told reporters, adding: "We reject them absolutely."

A Ugandan army spokesman also announced on Sunday that the country had "suspended all ongoing defence and military cooperation activities" with Germany.

However, Deschauer said that "there is no formalised military cooperation with Uganda... so there is nothing to cancel".

European diplomats reportedly raised criticisms about Kainerugaba in a meeting with Museveni's brother, Salim Saleh, earlier this week.

Local media reported that Saleh vowed to "rein in" the army chief.

Kainerugaba, who is considered most likely to succeed his 80-year-old father as president, is known for his colourful social media posts.

Rights groups say the government has accelerated its crackdown on opponents and critics ahead of elections in January, in which Museveni hopes to extend his 40-year rule.