Ethiopian political leaders have signed a declaration renewing a deal to try to end violence and launch an investigation into election complaints.
Security forces have zealously enforced the ban on protests
At least 36 people died last week when security forces fired at protesters, alleging fraud in the polls.
Opposition leader Hailu Shawel has been freed from house arrest, the European Union's Tim Clarke told the BBC.
Prime Minister Meles Zenawi has extended a ban on demonstrations until final results are announced on 8 July
Friday's EU-brokered agreement - signed by both the ruling Ethiopian People's Revolutionary Democratic Front (EPRDF) and the two main opposition coalitions - broke down when the opposition alleged the government could not be trusted - though it later withdrew the comments.
The electoral board will now begin investigations on Wednesday into more than 300 complaints in the 547 constituencies.
Three weeks after polling, final election results have not been declared - although provisional results suggest the ruling party had won a majority of seats in the parliament but had been comprehensively defeated in the capital, Addis Ababa.
Addressing the nation on Monday evening for the first time since last Wednesday's clashes, Mr Meles said the government had not intended to use force to quell the demonstrations, and regretted the loss of life but he blamed "criminal elements" not his security forces.
The protests were started by students last week
"Violating the law of the country and agitating violence is unacceptable."
Opposition leader Beyene Petros, of the United Ethiopian Democratic Forces (UEDF) told the BBC that, as part of a confidence building process, the government should release those arrested in the protests and start legal action against those he said had summarily massacred civilians.
Human rights workers say more than 3,000 people have been arrested since the polls.
The United States on Monday condemned the use of "excessive force" in Ethiopia during the protests in the capital, Addis Ababa.
"We urge the government to respect the rule of law, international principles of human rights, and due process with regard to those arrested or detained," State Department spokesman Sean McCormack said in a statement.
An opposition group says one of its MPs-elect was shot and killed by police at the weekend, south of the capital.