Human rights groups say at least 157 died in Monday's protest
Guinea's military leader has called for a government of national unity days after dozens of opposition supporters died when protests turned violent.
The rally was triggered by rumours that Moussa Dadis Camara, who seized power in a coup, would run for president.
Capt Camara has called for "a commission of inquiry backed by the UN" to investigate the deaths.
Meanwhile, the ruling National Council for Democracy and Development said it sought a transition government.
"The CNDD asks for [...] the formation of a government of national unity integrating members of different political parties and tasked with transition," presidency official Mandjou Deoubate said on state television.
The African Union has given Capt Camara until mid-October to confirm he will not stand in presidential elections planned for 31 January.
The military rulers - who have held power in the country since last December - also called for an African leader to be appointed as a mediator between the political parties.
Local activists say at least 157 people were killed when soldiers fired directly at protesters, though government officials put the death toll at 57.
The interior ministry said most of those who died were not shot dead but were trampled to death.
The UN human rights chief, Navi Pillay, on Wednesday condemned the crackdown, during which soldiers were reported to have raped women in the streets.
"Monday's bloodbath must not become part of the fabric of impunity that has enveloped Guinea for decades," she said.
Capt Camara has pledged to investigate why troops opened fire and announced two days of mourning beginning on Wednesday.
There has been worldwide condemnation of the violence, with the UN urging the authorities to show restraint, and regional economic bloc Ecowas reportedly threatening sanctions.
France has said it has suspended military co-operation with its former colony and it is considering freezing aid to the country.
But analysts say international bodies have little leverage as Guinea is a resource-rich, wealthy nation enjoying heavy investment from foreign mining firms.
Africa analyst Paul Melly told the BBC that Guinea's former ruler, Lansana Conte, survived years of aid suspension from the EU without caving in to demands for political reform.