The culture of violence in politics must be brought to an end throughout the country, and particularly now in the south-west

President Obasanjo

Mr Ige was shot dead at his home in the south-western city of Ibadan.

He had been enmeshed in political turmoil in the south-western Osun state which polarised his Alliance for Democracy party.

Last week, a long-running feud between Osun state Governor Bisi Akande and his deputy, Iyiola Omisore, led to the death of a state legislator.

Nothing stolen

Mr Ige, 71, backed Mr Akande, who had been deputy governor when Mr Ige was governor of Oyo state.

Bola Ige himself was recently attacked by a mob in the town of Ile-Ife, where many politicians are reported to have gone into hiding.

"The culture of violence in politics must be brought to an end throughout the country, and particularly now in the south-west," said a statement from the presidency.

Gunmen burst in to Mr Ige's residence at 2200 local time and forced his wife, Judge Tinuke Ige, to leave their bedroom, the Associated Press news agency reported, quoting one of Mr Ige's relatives.

He was then shot once in the chest, AP said.

Mr Ige was pronounced dead on arrival at Oluyoro Catholic Hospital.

None of the other people in Mr Ige's home were harmed and nothing was stolen, an army official told Reuters news agency.

Security guards had been just given permission to leave for a dinner break, said the official.

Serious blow

Mr Ige's death will be a serious blow to his friend, President Olusegun Obasanjo, the country's civilian leader who took over from the military in 1999.

President Olusegun Obasanjo was a close ally of Ige

"We received the news with great shock," Information Minister Jerry Gana told Reuters, as he arrived at the presidential villa for the emergency cabinet meeting.

Mr Ige represented a rival party to Mr Obasanjo's People's Democratic Party, but Mr Obasanjo made him power minister and later justice minister.

Mr Ige was seen as an important ally, not least because of his strong standing within the Yoruba community which dominates south-western Nigeria.

Mr Ige had also been outspoken against aspects of Islamic Sharia law which has been introduced in 13 of the country's northern states over the past year.

The issue has led to riots in which more than 3,000 people have been killed - a situation that seriously threatens the country's stability particularly in the run up to parliamentary and presidential elections next year and in 2003.

The BBC's Chris Simpson says the government's priority now will be to ensure that the murder does not set off a fresh round of retaliatory violence.