Three opposition leaders and a human rights activist in Ethiopia say they will go on hunger strike from Monday in protest against their detention.
Journalists were invited into the police station
The four were arrested at the beginning of this month during violent protests over May's disputed election results.
They have not been formally charged but Prime Minister Meles Zenawi says they could be tried for treason.
CUD leader Hailu Shawel and two top party officials say their detention is politically-motivated.
"We have decided to go on hunger strike indefinitely beginning Monday, 28 November 2005 - we will take only liquids," said top CUD (Coalition for Unity and Democracy) official and mayor-elect of Addis Ababa, Berhanu Nega, speaking to journalists at Ethiopia's central investigation centre.
"This is a political case, not a criminal one," said Mr Hailu.
Prominent human rights activist Professor Mesfin Woldemariam and deputy CUD leader Birtukan Midek are also being held.
Correspondents say granting the media access to the detainees was an attempt by the government to show the opposition leaders are not being ill-treated.
Some 8,000 people have been freed since the protests organised by the opposition, claiming that May's elections were rigged.
There are no official figures for the number who remain in custody but diplomats say it is at least 3,000.
At least 46 people were killed when security forces broke up the protests.
The international community has called for the immediate release of all political detainees.
Mr Meles' Ethiopian People's Revolutionary Democratic Front won a majority in polls but the opposition gained many seats.
The opposition is made up of the two broad groupings - the CUD and the United Ethiopian Democratic Forces, which unlike the CUD, have taken up their parliamentary seats.