Nigeria's new military ruler, General Abdulsalem Abubakar, has addressed the nation, which is angry and shaken following the death of the imprisoned opposition leader, Chief Moshood Abiola.

Chief Abiola died on Tuesday of an apparent heart attack just hours before he was due to be released.

The opposition leader was widely believed to be the winner of the country's 1993 elections. But he was imprisoned by the late General Sani Abacha, and spent four years in solitary confinement.

As news of Chief Abiola's death spread, at least 19 people were killed in rioting in Lagos and other parts of south-west Nigeria.

Nation 'facing critical times'

Hilary Andersson: "a moment of respite while Nigerians watched their leader speak"

In a televised address, Nigeria's military leader, Gen Abubakar, appealed for calm.

He offered his "heartfelt condolences" to Chief Abiola's family and said the millionaire-turned-politician was on the brink of being released from prison.

Gen Abubakar said the nation was facing "critical times" and urged Nigerians to remain calm. He said the nation's grief could not be assuaged by lawlessness or wanton destruction.

Gen Abubakar: pledge to restore democracy

"National reconciliation and the restoration of democracy" was imperative, he said. But he made no mention of new elections. He said he would address the nation on such matters "in due course".

However, the Commonwealth Secretary General, Chief Emeka Anyaoku said he believed Gen Abubakar was on the verge of announcing a new timetable for restoring civilian rule.

Chief Anyaoku said that he had talked to Gen Abubakar on Tuesday evening and he described the Nigerian leader as "determined to usher in democracy."

General Abubakar: "I appeal to you all to be calm despite your understandable grief."

Earlier on Wednesday Gen Abubakar sacked his secretive inner cabinet in a bid to calm the violent unrest sparked by the sudden death of Chief Abiola. The hard-line cabinet had ordered many of the human rights abuses of Gen Abacha's regime, including the execution of the writer Ken Saro-Wiwa.

However, the country's Provisional Ruling Council, the core of the ruling military regime, was left untouched.

Mystery surrounds death

Many of Chief Abiola's allies voiced suspicion over the manner of his death, and his daughter Wuru said she believed he had been killed.

She said: "(He died) either because medical neglect brought on a heart attack or because they poisoned him."

US Under Secretary of State Thomas Pickering: "We hope Nigeria's people remain calm."

It is believed the government was trying to get Chief Abiola to give up his presidential mandate in exchange for his freedom, although as of a few days ago he had not committed himself to this in writing.

US President Bill Clinton dismissed speculation that the death was a result of foul play, and the United Nations Secretary General, Kofi Annan, called for calm.

Pictures released of Chief Abiola meeting Mr Annan last week showed him in apparent good health, although he had lost weight. He had suffered bouts of illness in jail.

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