President Luiz Inácio Lula da Silva in Brasília on Monday. He is taking on a right-wing candidate in a runoff on Oct. 25.

The Irkutsk Anti-Plague Research Institute of Siberia and the Far East in Irkutsk, Russia, on Wednesday. The researcher who died worked in the lab.

An infectious-diseases hospital in the town of Shelekhov, Russia, on Monday. The mayor has urged residents “not to spread rumors.”

The Rabaa al-Adawiya mosque in Cairo, which was the center of a Muslim Brotherhood protest in 2013.

Supporters of the right-wing presidential candidate Flávio Bolsonaro waved American flags and brandished a blowup doll of President Trump clutching an imprisoned President Luiz Inácio Lula da Silva at a rally this month in São Paulo, Brazil.

The Brazilian Supreme Court Justice Alexandre de Moraes has become a polarizing figure in the debate over policing online speech.

The United Nations headquarters on Monday as world leaders convened in New York for the General Assembly.

Migrants at a Red Cross food distribution site in Ceuta, Spain, last week.

A class at the Helsinki Upper Secondary School of Media Arts. Educators in Finland teach students how to spot fake news.

A campaign event last week for Prime Minister Nikol Pashinyan ahead of Armenian parliamentary elections.

Outside a mosque in Peacehaven, England, after an arson attack in October.