At least 157 opposition supporters are now believed to have died after Guinea's troops opened fire on a mass protest in the capital, Conakry, a human rights group has said.
"According to hospital sources that we have spoken to, 157 dead and 1,253 injured have been registered," Thierno Maadjou Sow, the president of the Guinean Human Rights Organisation, said on Tuesday.
Sow told the Reuters news agency that the figure did not include the bodies of an unknown number of demonstrators killed which were never delivered to hospital in the city.
Opposition parties, which organised the demonstration amid speculation that Moussa Dadis Camara, the country's military leader, would stand in forthcoming elections, had earlier said that at least 128 people had died.
The shootings took place on Monday after about 50,000 protesters gathered outside a stadium in defiance of an official ban on the demonstration.
Camara, who has not yet formally announced his intention to stand in the January 31 poll, said that the killings were beyond his control.
"Even I, as head of state in this very tense situation, cannot claim to be able to control those elements in the military"
Moussa Dadis Camara, Guinea's military leader
"Those people who committed those atrocities were uncontrollable elements in the military," he told Radio France International late on Monday.
"Even I, as head of state in this very tense situation, cannot claim to be able to control those elements in the military.''
But there was widespread international condemnation of the bloody crackdown.
The African Union Commission, condemned the "indiscriminate firing on unarmed civilians", and urged Guinean officials to respect freedom of expression and assembly.
"In this respect the commission is preparing a report on the developments in Guinea and possible measures to be taken, including sanctions," it said in a statement.
The AU suspended Guinea's membership after Camara seized power in a bloodless coup last December.
Ban Ki-moon, the UN secretary-general, also deplored the "excessive use of force" and said he was "shocked by the loss of life, the high number of people injured and the destruction of property".
|Camara, left, seized power after the death of President Lasana Conte last year [AFP]
France, Guinea's former colonial ruler, also condemned "the violent repression exercised by the army against the opposition and civil society during a peaceful demonstration held in Conakry".
Paris called on the military government to "show responsibility and to listen to the Guinean people's legitimate aspiration to democratically choose their leaders".
Human rights organisations and opposition politicians have said that there were reports of demonstrators being put to death with bayonets and women being raped by soldiers.
Corinne Dufka, the senior West Africa researcher at Human Rights Watch, said that the killing of dozens of unarmed protesters was "shocking even by the abusive standards of Guinea's coup government".
"Guinea's leaders should order an immediate end to attacks on demonstrators and bring to justice those responsible for the bloodshed," she said.
Camara had pledged not to stand for the presidency when he seized power after the death of Lasana Conte, the president, but he is reported to have told a number of people in recent weeks that he will run next year.
Al Hassan Silah, a Conakry-based journalist, told Al Jazeera: "He has started saying that, as a citizen, he has that right and nobody should dictate what he can do.
"He appears to have gone back on his promise and that is what has angered people here and led to the demonstration at the stadium in Conakry."