Kampala - Ugandan President Yoweri Museveni has fired the secretary-general of the country's ruling party, officials said Wednesday amid signs of a possible power struggle between the veteran politicians.

Amama Mbabazi, 65, was ousted as head of the National Resistance Movement, but remains in his post as Uganda's prime minister, the NRM's new head Richard Todwong said.

Mbabazi has been a long-term ally of Museveni, aged 69 and Uganda's leader since 1986, but there have been signs recently that he was emerging as a potential challenger within the party.

The move comes shortly after Museveni was yet again chosen as the NRM's candidate for presidential elections due in 2016.

“I have been tasked by the party to coordinate its activities as secretary-general until the next general elections,” Todwong told AFP, without giving details of why Mbabazi had been dropped.

But the state-owned New Vision newspaper said some NRM members were facing a “disciplinary hearing... for contravening party rules” and that Mbabazi was suspected of having tried to lobby against Museveni being allowed to stand for yet another term in office.

Museveni's press secretary Tamale Mirundi refused to comment on the sacking.