At least 10 people were killed in clashes Sunday between police and protesters, opposition activists said, as Guinea held a bitterly disputed referendum that critics say is a ploy by the president to stay in power.
Anti-government forces came under fire by security forces who "carried out massive arrests, fired blindly, cruelly molested (and) killed at least 10 people," the FNDC, an umbrella opposition group, said in a statement.
The FNDC, grouping opposition parties and civil society organisations, called for fresh protests Monday and Tuesday.
The authorities could not immediately be reached to confirm the casualty toll.
Alpha Conde, who became the West African country's first democratically elected president in 2010, is proposing a change to the constitution to codify gender equality and introduce other social reforms.
But his opponents fear the real motive is to reset presidential term limits, allowing Conde, 82, to run for a third spell in office later this year -- a scenario that his government has not discounted.
Early Sunday young people attacked police deployed outside a polling station in a suburb of the capital Conakry, according to an AFP reporter and other witnesses. In another school nearby, voting equipment was vandalised.
A 28-year-old man was shot dead and several others wounded in another Conakry suburb, Hamdallaye, the victim's brother confirmed to AFP. Officials did not respond to AFP's requests to confirm the death.
Clashes also broke out in other Conakry suburbs and elsewhere in the country, a former French colony.
Since October, Guineans have protested en masse against the possibility of Conde extending his grip on power.
- 'Taking things lightly' -
Critics questioned the fairness of Sunday's vote, which took place amid mounting concern about the spread of the novel coronavirus in Africa, including two cases officially reported in Guinea.
"I have the impression our country is taking things lightly," said Amadou Oury Bah, a banker and politician who suspected the authorities were more interested in their electoral campaign than keeping the country safe from the pandemic.
Conde postponed the referendum, originally scheduled for March 1, late last month over doubts concerning the country's electoral roll.
Some 7.7 million people were on the register, out of a total population about 13 million people.
The government says it has scrubbed the problematic names on the urging of an expert team from the West African bloc ECOWAS.
But Guinea's embattled opposition still doubts the vote's credibility.
Cellou Diallo, a former premier and the head of the leading UFDG opposition party, said the process of cleaning up the electoral roll had been opaque.
The UFDG and other opposition parties are boycotting both the referendum and a parliamentary election taking place at the same time.
- 'Authoritarian' Conde -
Conde, a former opposition figure who was jailed under previous hardline regimes, was Guinea's first democratically elected president.
Since voters returned him to office in 2015 for his second and final five-year term under the current constitution, critics say he has become increasingly authoritarian.
The draft constitution would limit presidential terms to two but extend the length of the term to six years, potentially enabling Conde to govern for another 12 years.
The government argues that the new constitution would usher in sorely needed changes in this conservative country, especially for women.
These would include banning female genital mutilation and under-age marriage, and giving spouses equal rights in a divorce.
Conde has not denied that he might use the new constitution to seek another term when his second runs out this year.
He told French media last month that there was "nothing more democratic" than holding a referendum and it was up to his party to determine whether he would run again.