The long-serving president of Equatorial Guinea, Teodoro Obiang Nguema, is on a state visit to Zimbabwe to thank President Robert Mugabe for stopping 70 mercenaries from invading his country two years ago. The Mugabe government is hoping the visit will yield a lucrative oil deal for Zimbabwe, which is critically short of foreign exchange to buy fuel.

The Zimbabwe government made clear from the very beginning how much it welcomed the visit by President Obiang. He was met at the airport by Mr. Mugabe and groups of enthusiastic ruling-party loyalists, as well as a 21-gun salute. He was the guest of honor at an official banquet, after which he was given a tour of key industrial installations.

Equatorial Guinea is one of Africa's richest countries, following discovery of rich oil fields. It also has a shocking human rights record, according to Amnesty International, which says its small population lives in abject poverty and enjoys few civil liberties.

Though the Obiang government has drawn international criticism because of its rights policies, it has good relations with Zimbabwe. After a tip from South African intelligence, a group of 70 suspected mercenaries was arrested at Harare airport in March 2004, when they stopped to collect weapons to be used to stage a coup in Equatorial Guinea.

The mercenaries were found guilty in a Harare court on weapons and immigration charges. They were released last year, except for group leader Simon Mann, a Briton who is still serving his four-year sentence in Zimbabwe's maximum security prison.

Five South Africans are serving long, harsh sentences in Equatorial Guinea in connection with the same plot, and their families are unable to visit them.

British businessman Mark Thatcher, son of former British prime minister Margaret Thatcher, pleaded guilty in South Africa to unwittingly taking part in the plot.

Mr. Obiang said he is in Zimbabwe to discuss security issues and a possible oil agreement with with the Mugabe government.

Zimbabwe is in its deepest financial crisis, and several government officials expect Equatorial Guinea to provide some kind of lifeline. Zimbabwe has been unable to afford to import fuel for consumers for a year.