Detained Ethiopian opposition leaders and editors will face treason charges for their part in last week's protests, the prime minister has said.
More than 40 protesters died in a week of violence
"They will not be released and they are accused of engaging in insurrection... they will have their day in court," Meles Zenawi told journalists.
If found guilty they could face the death penalty. Some 46 protesters died in the election demonstrations.
But the prime minister said personally he did not support the death penalty.
"It is for the prosecution and courts to decide, but if I have any say on it I would prefer prison sentences rather than death sentences," Mr Meles said.
The unrest between opposition supporters and the security forces first erupted last Tuesday in the capital, Addis Ababa, after the opposition accused the government of rigging the 15 May elections.
These were the worst disturbances in Sub-Saharan Africa's second most populous country since protests ignited after the May polls, when some 36 people died and hundreds were arrested.
Mr Meles told the BBC he had evidence that the opposition leaders had made it clear they were trying to overthrow the government and that amounted to treason.
The prime minister has previously said he regretted last week's deaths and had called for an independent commission to investigate whether police had used excessive force to quell the unrest.
He confirmed on Tuesday that the police had used live ammunition because the use of water canon had not quelled the unrest.
He claimed that demonstrators had thrown grenades at the police and attacked buses.
"This is not your run-of-the-mill demonstration. This is an Orange Revolution gone wrong," he is quoted by Reuters as saying.
"I think the worst is behind us," Mr Meles said.
The BBC's Mohammed Adow in Addis Ababa says despite a week-long stay-away called by the opposition, the capital is back to normal.
Doctors said most of the dead had been shot in the chest
Although there is some security force presence on the streets, he says.
On Monday, 24 opposition leaders appeared in court - they were not charged, but ordered to be held for another 14 days.
They included the chairman of the Coalition for Unity and Democracy, Hailu Shawel, the vice-chairman, Berhanu Nega, and the prominent human rights activist Mesfin Wolde Mariam.
Two editors of private newspapers also appeared.
Since the unrest began, the private press - especially in Amharic - stopped publishing on the orders of the government, our correspondent says.
Mr Meles says two groups of people were detained - first the leaders of the "insurrection" and second rioters, most of whom he described as unemployed youths.
He confirmed that thousands of youngsters had been rounded up and taken to detention camps outside the capital.
The international community has called for the immediate release of all political detainees.
Mr Meles' Ethiopian Peoples Revolutionary Democratic Front won a majority in polls but the opposition gained many seats.
Last week's protests began after the CUD refused to attend parliamentary sessions.
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.
Over the weekend, ambassadors from European Union countries and the United States issued a strongly-worded statement , calling on the government and the opposition to re-open their political dialogue.