GENEVA (AP) — The U.N. human rights office says security forces in Venezuela detained nearly 700 people in one day last week amid anti-government protests — the highest such tally in a single day in the country in at least 20 years.

Rights office spokesman Rupert Colville said Tuesday that 696 people were detained on Wednesday alone. Overall, some 850 were detained between Monday and Saturday, including 77 children.

Colville said “more than 40 people” are now believed to have been in killed “in different manners” amid the recent protests, including 11 people reportedly killed by “unidentified individuals” linked to incidents of looting. He said one member of the Bolivarian Guard was reportedly killed in the state of Monagas.

He told reporters in Geneva that officials were investigating reports of ill-treatment of detainees.