Two policemen and six protesters have died and dozens have been wounded in clashes sparked by poll protests in Ethiopia's capital.
Most of the wounded went to the Black Lion Hospital
Some 250 riot police went to disperse stone-throwing protesters who had set up roadblocks with burning tyres in the central Mercato area of Addis Ababa.
These are the first disturbances in the capital since June's post-election protests when some 36 people died.
The main opposition party began fresh protests on Monday over the polls.
"Police have taken steps to bring to justice leaders of the opposition who they consider to be responsible for the deaths," a police statement said.
The main opposition party says several of its leades have been arrested in the hours after the disturbances.
The BBC's Mohammed Adow in Addis Ababa says that heavily armed police have shut many of the streets around the central shopping areas of Mercato and Piazza.
Stones litter the roads and shops are shut. Our reporter says many Muslims were out in the morning shopping in preparation for celebrations to mark the end of Ramadan on Wednesday.
Doctors were quoted as saying that most of the dead had been shot in the chest and those wounded were shot in the legs and arms.
Security forces were trying to prevent journalists from entering hospitals where the wounded have been taken.
But one of the wounded in hospital told AP news agency that police had fired indiscriminately at people on the streets, including those not involved in the protests.
"I was trying to get to work this morning but the road was blocked by riot police. I could see there was beginning to be trouble, so I turned around to go home, but everyone started running and the police started shooting and I was shot in my leg," Bukara Debele said from his hospital bed.
"They were shooting at anyone. People were falling over and screaming and the riot police were hitting them with batons".
Opposition protests against election results resumed on Monday as the government threatened legal action against the main opposition party, the Coalition for Unity and Democracy (CUD) - who are boycotting parliament.
The opposition say Meles rigged elections in May
Police arrested and revoked the licences of 30 taxi drivers who took part.
Information Minister Berhan Hailu blamed the violence on the CUD.
"The CUD has called for these demonstrations. It is part of their plan to disrupt peace and stability in the country."
Opposition spokesman Gizachew Shiferaw said police used excessive force.
"The trouble was incited by the government simply because people were supporting us by hooting their car horns," he told reporters.
"The CUD has only called for peaceful and legal measures, so to blame us for this violence is madness."
Prime Minister Meles Zenawi's EPRDF won a majority in polls but the opposition gained many seats.
The Ethiopian government has dismissed an assessment by European Union monitors that the elections failed to meet international standards.
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What should the police have done? These gangster should be punished. Their ultimate goal is to steal property of inocent citizens.
Ayalew Lemma, Addis
It was very frightening to see human beings hit as such in day light, in front of foreign and local journalists. I was just counting the very second that brings me death while running. When I reached a corner of a building, there were two very young boys who were shot and calling for help... I was not sure where they are hit... there was a lot of blood in their area. I have no time to help... I was just running... I am so surprised that the white diplomats keep quiet in such scenarios. I feel that we are left alone on earth. Who is going to stop this killing in Addis Ababa? Ethiopia is a land where the elected are being harassed by the non-elected and hated dictators. I am terrified even while typing this in an Internet cafe. Please help!
Getasew Derso, Addis Ababa, Ethiopia
I am sad that people are dead. I am a merchant having a shop in Mercato. I couldn't blame the police as they shot dead the protestors who are having the plan to rob the shops in Mercato and are trying to spoil the Muslim holiday to be celebrated tomorrow. How could u see the gangs who are trying to loot the houses (they have done the same things years ago in the central piazza of Addis Ababa) without taking an action? Those of u who are blaming the police, I am not sure about ur motive. I would like to tell the government to take any reasonalble action against the opposition leaders before they ruin our peace.
Tigabu, Addis Ababa, Ethiopia
Hours ago I saw the worst thing in my life. I was in around Piazza, near Cinema Amphere around 10am. Two persons had been shot and lying on the road. One of the two was dead. And the federal police came and handover the dead body's leg; and started to pull the body for a long distance on the asphalt road. Nobody can imagine what is happening here nobody! The police were shooting directly to the people after an hour. We are dying here no one seems to care I mean no one!
Observer, Addis Ababa, Ethiopia
Here in Ethiopia everything has arrived at the climax stage not only in the capital of Ethiopia but also in other parts of the country. Many of them are arrested and some of them are killed. No-one asks.
Tezera Z Tanadar, Bahirdar, Ethiopia
I was in Mercato this morning. People have been running here and there. It was started when the police stopped a taxi driver. High school students were against the police. I run away out of the area. I tell you the strike will continue.
Alemu, Addis Abeba, Ethiopia
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