The protests come in light of a nationwide lockdown to halt the spread of the coronavirus outbreak.
The U.N. rights chief warned Monday that countries flouting the rule of law in the name of fighting the novel coronavirus pandemic risk sparking a "human rights disaster".
United Nations High Commissioner for Human Rights Michelle Bachelet called on countries to refrain from violating fundamental rights "under the guise of exceptional or emergency measures."
"Emergency powers should not be a weapon governments can wield to quash dissent, control the population, and even perpetuate their time in power," she warned in a statement.
"They should be used to cope effectively with the pandemic -- nothing more, nothing less."
Her comments came after more than 200,000 people have perished in the pandemic and nearly three million have been infected worldwide by the novel coronavirus since it surfaced in China late last year.
Bachelet acknowledged that states have the right to restrict some rights to protect public health, but she insisted that any restrictions should be necessary, proportionate and non-discriminatory, and also limited in duration.
"There have been numerous reports from different regions that police and other security forces have been using excessive, and at times lethal, force to make people abide by lockdowns and curfews," she said, lamenting that "such violations have often been committed against people belonging to the poorest and most vulnerable segments of the population."
"Shooting, detaining, or abusing someone for breaking a curfew because they are desperately searching for food is clearly an unacceptable and unlawful response.
"So is making it difficult or dangerous for a woman to get to hospital to give birth."
- 'Incalculable damage' -
"In some cases, people are dying because of the inappropriate application of measures that have been supposedly put in place to save them," Bachelet said.
She also decried the mass arrests in some countries over curfew violations as "both unnecessary and unsafe."
"Jails and prisons are high risk environments, and states should focus on releasing whoever can be safely released, not detaining more people."
The U.N. rights chief also warned that efforts to rein in dangerous misinformation around the pandemic was in some cases being used as an excuse to crack down on legitimate free speech.
"It is important to counter misinformation, but shutting down the free exchange of ideas and information not only violates rights, it undermines trust," she said.
"Undermining rights such as freedom of expression may do incalculable damage to the effort to contain COVID-19 and its pernicious socioeconomic side-effects," she warned.
Bachelet also insisted that any exceptional measures or state of emergencies introduced in the name of fighting COVID-19 should be subject to proper parliamentary, judicial and public oversight to avoid abuses.
"If the rule of law is not upheld, then the public health emergency risks becoming a human rights disaster, with negative effects that will long outlast the pandemic itself," she said.