(Updates with jail term)
By Elias Biryabarema
KAMPALA, Aug 1 (Reuters) - A Ugandan court jailed a prominent academic on Friday for 18 months on cyber harassment charges stemming from a Facebook post that included sexually explicit criticism of long-ruling President Yoweri Museveni.
The verdict drew the ire of rights activists who accused the government of using laws about electronic communications to stifle political dissent.
Stella Nyanzi, a university lecturer and researcher who once called Museveni "a pair of buttocks", has drawn the government's wrath for her attacks on him. Her commentary, laced with profanity, is posted on her Facebook page and often shared widely by her followers.
She attended her sentencing session in a court in the centre of the capital Kampala via video link from a maximum security prison by the shores of Lake Victoria on the city's outskirts.
Nyanzi shouted vulgarities and flashed her breasts and a double middle finger on several occasions during the session.
Her offence stemmed from a Facebook post last year in which she said she wished Museveni, 74, had been burned up by the "acidic pus" in his mother's birth canal.
"My presence in your Court as a suspect and prisoner highlights multiple facets of dictatorship. I exposed the entrenchment of autocracy," she wrote in her most recent post, a poem about her court case. "I refuse to be a mere spectator in the struggle to oust the worst dictator."
Joan Nyanyuki, director for East Africa at human rights pressure group Amnesty International, said: "This verdict is outrageous and flies in the face of Uganda's obligations to uphold the right to freedom of expression ... and demonstrates the depths of the government's intolerance of criticism."
The verdict should be quashed and Nyanzi, who has been in jail since November last year, freed immediately, Amnesty said.
"The Ugandan authorities must scrap the Computer Misuse Act... which has been used systematically to harass, intimidate and stifle government critics," Nyanyuki said.
Critics say Museveni, in power since 1986, is increasingly becoming intolerant of dissent as resistance to his rule grows.
Nyanzi's lawyer, Isaac Ssemakkadde, told Reuters she had yet to decide on whether to appeal her conviction.
$1 = 3,690.0000 Ugandan shillings Editing by Duncan Miriri and Peter Graff