Jambula Tree was described as "witty and mischievous"

Monica Arac de Nyeko beat four other finalists to get the $20,000 (£10,000) prize for her story Jambula Tree.

It is about a relationship between young girls in a country where homosexuality is illegal.

"I'm not a lesbian but I do think it's a difficult subject, like... writing about Uganda's history," she said.

She's taking on a theme that Africans have been in denial about Publisher Becky Ayebia Clarke

The Caine Prize, announced in Oxford on Monday night, is considered a major award in African creative writing.

Jambula Tree was described as "witty and mischievous" by the judges.

Her publisher Becky Ayebia Clarke said when she first read the story she thought "how brave" Ms Arac de Nyeko was to take on the subject.

"In Africa these are not the kind of stories we're allowed to tell. She's taking on a theme that Africans have been in denial about - a theme about same-sex love."

'Walls'

"The Jambula Tree is about the relationship between two young girls in a very complex social setting in a community which does not look kindly at that relationship," Ms Arac de Nyeko told the BBC's Network Africa programme.

There are a lot of difficult things that I think we need to talk about and not build walls of huge emotion Monica Arac de Nyeko

"It's a combination of struggle and the power to dream and love," she said.

"There are a lot of difficult things that I think we need to talk about and not build walls of huge emotion so that they're almost impassable."

She said the jambula tree signified various things in the story.

"First of all the jambula tree is where you have the neighbour who has been stealthily watching the two girls - their relationship unfold - over a significant amount of time."

While, the small fruit from the tree represents breasts.

"Jambula in this story is also an image for breasts... they're teenagers so they could well be mosquito bites, in this case jambulas."

Praying

The Caine Prize can be given to an African writer who has been published on the continent or elsewhere.

The prize also includes a month as "writer in residence" at a US university.

During her acceptance speech, Ms Arac de Nyeko said the prize was a "very exciting time for Ugandan fiction" and that she would immediately call her sister.

"I'll get on the phone and get my sister to stop praying - because she's been on her knees probably for a very long time," she said.

Monica Arac de Nyeko was born in 1979 in northern Uganda - the scene of one of the world's longest civil wars.

The other writers on the shortlist were:

• Uwem Akpan (Nigeria) - My Parents' Bedroom

• EC Osondu (Nigeria) - Jimmy Carter's Eyes

• Henrietta Rose-Innes (South Africa) - Bad Places

• Ada Udechukwu (Nigeria) - Night Bus