Nigerian judges have adjourned¹ three cases aimed at clarifying who rules while ailing² President Umaru Yar'Adua is in hospital in Saudi Arabia.

尼日利亚法官推迟了三件针对澄清当病重总统在沙特治病时由谁掌权的案件。

Goodluck Jonathan (L) has been in charge since November

Government critics say the president acted illegally when he failed to hand power formally to his vice-president - sparking four legal challenges.

A court ruling on Wednesday backed the government, saying the constitution did not require such transfer.

Two adjourned推迟，中止 cases will be heard next week, the other has no fixed³ date.

Mr Yar'Adua has been receiving treatment for a heart condition since late November.

His prolonged absence led to rumours⁴ that he was brain damaged or even dead.

'Meaningless' ruling

The BBC's Caroline Duffield in Abuja says even senior cabinet ministers seemed to be mystified, openly admitting they did not know when he would return.

She says Nigerians are watching the court cases very closely after all the uncertainty⁵ and political anxiety of recent weeks.

Analysts⁶ said Wednesday's ruling by Judge Dan Abutu appeared to preserve保持，维持 the status quo现状 - that Vice-President Goodluck Jonathan was in charge, but could not be regarded as official head of state.

But human rights lawyer and opposition⁷ activist⁸ Femi Falana, who is bringing one of Thursday's cases, dismissed摒弃，开除 the ruling as "meaningless".

"Jonathan cannot act for Yar'Adua because no functions have been formally and directly delegated to委托给 him by Yar'Adua," the AFP news agency quoted him as saying.

Mr Falana is asking the court to annul⁹ all decisions taken by the cabinet during the president's absence.

But during a short hearing at Abuja's Federal Court he argued that Judge Abutu could not rule in his case because Wednesday's case was so similar.

Judge Abutu passed the case to another judge, but a date for the next hearing was not set.

In another of Thursday's cases, the Nigerian Bar Association is demanding that power is handed over formally to Mr Jonathan.

That case was adjourned until 21 January.

While a third case, in which a rights group wants Mr Yar'Adua declared "missing", was adjourned until 22 January.

No reason was given for the adjournments.

Mr Yar'Adua has not been seen in public since he was taken to hospital in November, but he gave an interview to the BBC on Tuesday saying he was recovering and hoped to be able to resume his duties.

Doctors say he is suffering from acute pericarditis急性心包炎 - inflammation炎症，发炎 of the lining¹⁰衬里，内层 of the heart.

He also has a long-standing kidney complaint.