Two military planes were intercepted while fuelling at the Manyama military airbase on the outskirts of Harare. They were bombed up, and their targets were believed to be Zimbabwe House, Mugabe's official residence, and his mansion in the suburb of Borrowdale Brook.

It's understood the pilots were detained. There's no information on where they are being held.

The three senior officers are currently under armed guard at their Harare homes, apparently because the government is anxious to isolate them from other officers. They are Maj Gen Angelbert Rugeje, Quartermaster at Army HQ, Col Ben Ncube, of the army public relations directorate, and Air Vice Marshal Elson Moyo, deputy commander of the air force.

Moyo is the younger brother of July Moyo, a former government minister who was fired by Mugabe in a disagreement over the vice-presidency. Vice Marshall Moyo was previously notorious for being sued for adultery with a policeman's wife.

The government is desperate to keep news of the attempted coup from the general public, and the power black-out was attributed to technical problems at the Hwange thermal power station.

Today I asked the Minister of Defence, Sydney Sekeramayi, for a comment. He told me: "I do not discuss military issues with journalists."

But in a speech to a police cadet passing-out parade last Friday, President Mugabe said the country was on high alert in order to counter any attempts to topple his government. Observers believe he may have been referring to this attempt, which would mean the plans were known by the government in advance of the attempt.

In a previous failed coup, a number of officers were arrested in late 1998 on charges of insurrection. The episode was reported in the independent newspaper the Standard, in January 1999, and the editor and writer were both arrested and tortured