A wave of anti-government unrest turned deadly in Ethiopia over the weekend, with Amnesty International on Monday putting the death toll at nearly 100.
The government earlier said only seven people had been killed, all of them in Bahir Dar, the capital of the north-western region of Amhara, as protesters clashed with police.
But Amnesty International said police had shot 30 people dead in the city.
In addition, 67 people were killed in clashes in Oromia, Ethiopia's largest region covering part of the south and west, the rights group quoted "credible sources" as saying.
Social media activists and witnesses, who spoke to dpa on condition of anonymity, earlier put the death toll in both regions at up to 25.
The demonstrators in Amhara and Oromia accused the government of rights abuses and marginalization of ethnic communities.
The Oromo are Ethiopia's largest ethnic group, constituting more than 30 per cent of the population of 100 million. The Amhara are the second-largest group.
In the capital, Addis Ababa, which is located in Oromia, "many people were beaten," said a witness who did not want to be identified.
"I saw others getting arrested. The government was out with guns in town. They're moving with so-called special forces. There was lots of shooting," he added.
In Bahir Dar, "social amenities, hotels, banks and individual-owned properties were attacked," the Amhara region's spokesman, Nigusu Tilahun, told state-affiliated Fana Broadcasting Corporate.
Witnesses reported police dispersing a smaller protest in the city on Monday, with shots echoing in the air.
Opposition representatives said protests were ongoing in several locations of Amhara and Oromia.
Oromia had previously seen months of protests against plans to extend the boundary of Addis Ababa amid concern that it could lead to farmers being displaced. Those protests had led to security forces killing more than 400 people, according to Human Rights Watch.
The boundary plan was abandoned, but resentment still festers among the Oromo community, which feels excluded from political and economic power.
In Amhara, the protests focused on federal boundaries drawn two decades ago that, according to local critics, cut off many ethnic Amharas from the region.
The government "should listen to the demands of the Ethiopian people and bring about national reconciliation that addresses the prevailing malgovernance and issues of identity," Chane Kebede, leader of the opposition Ethiopian Democratic Party, told dpa.
Amhara region spokesman Tilahun said that protesters had provoked police by throwing grenades, that the rallies were illegal, and that measures had been taken to "ensure the rule of law."
Amnesty expressed concern that the hundreds of people who had been arrested could be tortured.
The US embassy in Addis Ababa said that "we recognize that many of the demonstrations took place without authorization," but also stressed the "rights of all citizens, including those with opposition views, to gather peacefully and to express their opinions."
The government meanwhile blocked the internet for the second time in two months, allegedly to curb calls for protests.