An activist supporting the LGBT community, wearing a rainbow flag, walks past a gathering of Christians opposed to the decriminalisation of homosexuality, after a ruling by the High Court in Nairobi banning same-sex relations. Photo: AP Photo/Ben Curtis.

NAIROBI — Activists on Friday slammed the Kenyan High Court's decision to uphold a law banning same-sex relations as "a blow to human rights" and said they plan to appeal it.

"In handing down this most disappointing judgment, the Court has ruled that a certain sector of our society is not deserving of [human] rights," said Njeri Gateru, executive director of the Kenyan National Gay and Lesbian Human Rights Commission (NGLHRC).

Gateru blamed the ban for violence, blackmail, harassment and torture of homosexuals.

"They devastate people's lives and have no place in a democratic Kenyan society," he added.

Upholding the "archaic law" was a step backward in the progress Kenya made towards equality in recent years, said Human Rights Watch (HRW).

"Kenya's High Court has relegated people in same-sex relationships in Kenya to second-class citizenship," said HRW senior researcher Neela Ghoshal.

Amnesty International called the ruling "a major setback to the human rights discourse."

The reactions come shortly after a bench of three High Court judges ruled Kenya's ban on gay sex was not unconstitutional. 

"We are satisfied that the provisions [in the constitution] do not offend [homosexuals'] rights to dignity and privacy," said judge Roselyne Aburili.

There was no conclusive scientific proof that homosexuals "were born that way" and therefore needed special consideration within the constitution, Aburili explained the ruling.

Decriminalizing gay sex would "open a door to same-sex unions, which would go directly against the spirit of Article 45 of the constitution on marriage," the justice further said.

Some Kenyan religious leaders welcomed the ruling.

"Kenyans should be in a frenzy [and] thank God," Catholic bishop Alfred Rotich told journalists outside the court in the capital Nairobi.

Judge John Mativo said the petitioners had failed to provide credible evidence to demonstrate that the law discriminates against homosexuals.

The ban was constitutional because it specifies that "any person" is punishable under the law and does not single out homosexuals, said Mativo.

Friday's ruling comes after three Kenyan gay rights organizations filed petitions to declare sections of the penal code, which stem from the 1930s and make gay sex a crime, unconstitutional.

The case challenged the colonial-era laws, which criminalize homosexuality with a maximum jail sentence of 14 years.

Court hearings on the matter had been ongoing since February 2018.

Thirty-three African countries still have laws on the books that outlaw consensual same-sex relations, according to HRW.