The men have been held since March

A state prosecutor told the Zimbabwe court that the 66 men had attempted to acquire weapons from the state arms firm Zimbabwe Defence Industries.

The men say their plane landed in Harare in March en route to a job in the Democratic Republic of Congo.

A map of Equatorial Guinea's capital was found on board, the court heard.

Diamond mine

Police Chief Inspector Clemence Madzingo, who lead the search of the plane, said the map of Malabo was discovered along with other military equipment.

"Some of the goods, the uniforms and also the equipment, which resembled military [equipment] among other items, were specifically for a mission," he told the court on Wednesday.

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The men's defence lawyer Jonathan Samkange said the men were recruited in South Africa to guard a diamond mine in DR Congo.

He said they did not know what cargo their plane was collecting at Harare International Airport, Associated Press news agency reports.

"They were only told they were going to the DR Congo, what they were to be paid, and what services were required of them," he told the court.

Documents were produced in court alleging the group had attempted to buy assault rifles, ammunition, hand grenades, anti-tank missile launchers and mortar bombs.

Last month former British SAS captain Simon Man, the alleged leader of the 70 arrested in March, admitted trying to procure dangerous weapons.

But he rejected a second charge of purchasing the weapons, insisting that the deal never went through, Reuters news agency reported.

Death Penalty

Most of the men, who all hold South African passports, earlier admitted to the lesser charges of breaking immigration and aviation laws at their trial held in a high security prison.

Three men including Mr Mann did not face the aviation and immigration charges because they were already in Zimbabwe when the plane landed.

The Zimbabwean government recently signed an extradition deal with Equatorial Guinea, where other South Africans are being held on suspicion of being the advanced party in the alleged plot.

The group's lawyers had appealed to the South African government to extradite them there instead, so they would not face a possible death penalty.

But South Africa's highest court upheld a June ruling against ordering the government to seek their extradition.

Those being held in Equatorial Guinea are due to go on trial on Monday in the capital, Malabo.