Nigeria's Vice President takes over from ailing president

Jonathan accepted the post hours after the vote, saying in a speech broadcast nationwide: "The circumstances in which I find myself assuming office today as acting president of our country are uncommon, sober and reflective."

Parliament's decision sent a powerful political message to Yar'Adua's supporters but heightened political turmoil in Africa's most populous country, which had been without an active president for over two months.

Amid warnings the instability was dangerous in a country with a history of military takeovers, Jonathan commended the security services for "their loyalty and devotion to duty during this trying period".

"I am deeply humbled and honoured by this great call to duty," he said.

Yar'Adua has been in hospital in Saudi Arabia since November 23 with a serious heart condition and critics say crucial government business is being left unattended.