Hundreds of people gathered outside the courtroom in Lagos as Mohammed Abacha, 29, was charged alongside General Abacha's security chief, Major Hamza al-Mustapha, and three other security officials.

General Abacha: Annulled elections

The presiding judge, Justice Dele Gbogodo, refused an application for bail and adjourned the case until 17 November.

The BBC's Barnaby Phillips in Lagos said Mohammed Abacha and Major al-Mustapha looked calm and relaxed and shared jokes together.

Major al-Mustapha waved and smiled at the crowd outside who had gathered to shout abuse.

Kudirat Abiola - one of the most vocal critics of General Abacha - was shot dead in a Lagos street in June 1996.

Her husband was widely believed to have won the 1993 elections which were annulled by the military when General Abacha seized power.

Moshood Abiola was jailed for his refusal to renounce claims to the presidency. He died in prison from a heart attack, a month after General Abacha himself died.

Bank accounts frozen

Major al-Mustapha and another accused, Lieutenant-Colonel Ibrahim Yakassai, also face murder charges over the death in prison in 1997 of Major-General Shehu Musa Yar'Adua, who was deputy to current President Olusegun Obasanjo when he was a military ruler from 1976 to 1979.

It is alleged that Maj-Gen Yar'Adua was poisoned by a lethal injection.

Both Maj-Gen Yar'Adua and Mr Obasanjo were jailed by General Abacha in 1995 for allegedly plotting against the regime.

In a separate development, Switzerland has ordered the freezing of all bank accounts in the names of General Abacha and his relatives.

The Federal Office for Police Affairs said the accounts were provisionally frozen on Wednesday after Nigeria asked Switzerland to block all accounts and seize bank records relating to the Abachas.

Swiss police did not specify the amount under investigation but said four banks in Geneva and one in Zurich were involved.