Nigeria's acting¹ President Goodluck Jonathan has been sworn in as head of state following the death of President Umaru Yar'Adua after a long illness.

尼日利亚总统亚拉杜瓦病逝之后，代总统古德勒克·乔纳森宣誓就职。

Mr Jonathan, in charge since February, will appoint a deputy and serve out the rest of the current presidential term until elections due next year.

Mr Yar'Adua died late on Wednesday in the capital Abuja.

Thousands attended the funeral in his home town of Katsina. Nigeria has declared seven days mourning.

Mr Jonathan took the oath（就职宣誓） of office in front of government ministers and other officials in Abuja almost 12 hours after Mr Yar'Adua died. The ceremony was performed by Chief Justice Alloysius Katsina-Alu.

Afterwards he made a brief address, saying his administration was committed to pursuing electoral reform and the fight against corruption² "with greater vigour³（活力，气势） ".

"While this is a major burden on me, and indeed the entire nation, we must - in the midst of such great adversity（逆境，不幸） - continue to gain our collective efforts towards upholding（赞成，支撑） the values which our departed leader represented," Mr Jonathan said.

He added: "One of the true tests will be that all votes count, and are counted, in our upcoming presidential election."

The BBC's Karen Allen says that all eyes will now be on the figure President Jonathan - who is from the Christian⁴ South - appoints as his deputy.

By tradition the presidency⁵ alternates between the Muslim North and the Christian South, and whomever he selects is likely to be seen as the presidential candidate for the ruling party the PDP, she says.

However, some analysts⁶ believe that Mr Jonathan could still strengthen his political power base, defy（蔑视，挑衅） religious convention and run for office himself.

Condolences paid

Mr Yar'Adua, who was 58, was buried in a Muslim ceremony in Katsina state.

Businesses and shops closed down as a sign of respect.

Soldiers and police officers accompanied his body on the flight to Katsina in the country's Muslim north.

There, mourners carried his body on their shoulders on a bamboo stretcher（担架） into a football stadium for a service.

Among chants of "God is great", the body - in a simple coffin⁷（棺材） - was buried at a cemetery⁸ near his home.

Mourners carried Yar'Adua's body, covered by Nigeria's green and white flag, on a bamboo stretcher to the open field for prayers and then burial at a nearby cemetery（墓地，公墓） .

"The death of President Yar'Adua is a great loss to democracy and a loss to the country and the whole of Africa in general," Ibrahim Ahmed told Reuters news agency.