The United Nations has said it will send an envoy to Equatorial Guinea after officials there announced that they had thwarted a December 24 coup attempt mounted by foreign mercenaries against President Teodoro Obiang Nguema.

A spokesman said Thursday that the UN's West Africa envoy, Francois Louceny Fall, would travel to the capital, Malabo, next week.

He said that while "little information" was available about the alleged coup attempt, "we condemn all attempts to seize power unconstitutionally" in the country.

Malabo's security minister, Mahamat Zen Cherif, made a televised statement on Wednesday saying that a group of mercenaries from Chad, Sudan and Central African Republic had tried to infiltrate Equatorial Guinea at the instigation of "certain radical opposition parties."

Hours after his televised statements, state broadcaster TGVE reported clashes on the border with Cameroon in which one "mercenary" was killed. Then, on December 27, Cameroon said it arrested 38 heavily armed men at the border, including an ex-general from the Chadian army.

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Opposition activists arrested

A day later, dozens of activists from Equatorial Guinea's main opposition Citizens for Innovation (CI) party were detained at its headquarters in the capital, and in the port city of Bata.

The party, which denies playing any part in the reported coup attempt, said many of its activists had already been arrested after a November 12 general election, in which 75-year-old President Obiang won a landslide victory with 92 percent of the vote.

Opposition parties have claimed that the results were fraudulent.

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Alleged mistreatment

CI coordinator Mariano Ona told DW that party activists were being mistreated while under arrest.

"We currently have 147 members of our party arrested, being tortured every day. We have no water or food. And they do not let anyone leave or enter this place," Ona said.

Ona said that the government had not informed them why they were being detained and called on the international community to intervene.

"I want an international intervention to mediate the situation. When there is an international intervention, I hope that dialogue will be established. We are an opposition party, and when the government is mistreating the population, there need to be demands," he said.

Ona also complained that Equatorial Guinea was a "dictatorial country" without a free press, a statement that appears to be borne out by the fact that Facebook, WhatsApp and VPNs have been blocked.

Oil-rich, but impoverished

Equatorial Guinea is one of the biggest oil producers in sub-Saharan Africa, but many of the country's 1.2 million people still live in poverty.

President Obiang, Africa's longest-serving leader, came to power in 1979 after ousting his own uncle, Francisco Macias Nguema, who was shot by a firing squad.

Last year's poll saw Obiang re-elected to a fifth seven-year term.

tj/rt (AFP, LUSA)