Muyassar Zargarova, the mother of one of the Tajik suspects in the terrorist attack outside Moscow, said her son had never exhibited signs of extremism.

Sidewalk construction in Tianjin. Last year thousands of residents were evacuated from apartments in the city after nearby streets split apart.

President Biden with President Ferdinand Marcos Jr. of the Philippines and Prime Minister Fumio Kishida of Japan at the White House on Thursday. “I want to be clear, the United States defense commitments to Japan and to the Philippines are ironclad,” Mr. Biden said.

Nazi doctors and scientists on trial at Nuremberg in 1947 for human experiments, murders and other atrocities during the Holocaust.

According to the W.H.O., the lack of access to corrective eyewear inhibits learning among students, increases the likelihood of traffic accidents and forces middle-age factory workers and farmers to prematurely leave the work force.

A market in the suburbs of Moscow, where many people from Central Asian countries, such as Tajikistan, work.

Some Western officials have said that when an attack failed to materialize immediately after a U.S. warning, Russia appeared to have lowered its guard.

Tourists outside of the Colosseum in Rome on Saturday. City leaders have proposed a new, pedestrian-friendly area in the center of the city, which supporters say would promote ancient Roman history.

Lynn Kilgallon, a research fellow at the Virtual Record Treasury of Ireland, at the Public Record Office of Northern Ireland in Belfast.

The view of the roof of the King’s College Chapel in Cambridge, England, with recently added solar panels.

Scorching temperatures this month in São Paulo, Brazil.

Crocus City Hall, the site of the terrorist attack in Moscow.

Landfills are the third-largest source of human-caused methane emissions, according to the Environmental Protection Agency.

Security forces on the street after Friday’s attack on a concert hall outside Moscow that killed at least 143 people.

Saidakrami Murodali Rachabalizoda, one of the men accused of the attack at a concert hall near Moscow that killed 139 people, in a Moscow courtroom.

Crowds in Moscow, including men wearing traditional Kyrgyz hats, leaving floral tributes at the concert hall that was the site of the attack.

President Vladimir V. Putin in the Grand Kremlin Palace two days before a terrorist attack on a concert hall in Moscow.

A makeshift memorial on Tuesday in front of the burned-out Crocus City Hall, the site of the deadly terrorist attack.

Saidakrami M. Rajabalizoda, a suspect in the Crocus City Hall shooting on Friday, is escorted by police and FSB officers in the Basmanny District Court in Moscow, on Sunday.

Lining up on Sunday in a Moscow suburb to place flowers in memory of the victims at the scene of the attack.

The damaged Crocus City Hall concert venue in Krasnogorsk, Russia, on Sunday. The head of the U.S. military’s Central Command said last week that ISIS-K “retains the capability and the will to attack U.S. and Western interests abroad in as little as six months with little to no warning.”

Scores of people brought flowers to a memorial at Crocus City Hall, where the attack took place, on Sunday.

Police officers outside the Crocus City Hall concert venue on Saturday after the attack outside Moscow on the day before.

People bringing flowers to a memorial on Saturday for the victims of the terrorist attack in the Moscow area.

A makeshift memorial on Saturday for the victims of the Crocus City Hall concert attack in Moscow.

Taliban police officers in Jalalabad, Afghanistan, in 2021. The area was frequently a target of attacks by Islamic State Khorasan militants in the months after the Taliban seized power in the country.

People brought flowers on Saturday to an impromptu memorial for the victims of the concert hall attack in Moscow.

Edmund Shklyarsky, left, the vocalist for Piknik, performing at a music awards ceremony in 2016 at Crocus City Hall in Moscow, in a photo released by the Russian state news media.

A billboard on Saturday noted the date of the concert hall attack in Moscow.

A member of the Taliban inspected the scene of an operation against militants from the Islamic State Khorasan on the outskirts of Kabul, Afghanistan, in November 2021.

President Vladimir V. Putin of Russia at the Kremlin on Wednesday. The terrorist attack outside Moscow a few days later was a blow to his aura as a leader for whom national security is paramount.

After Hurricane Fiona hit Canada, a 19th-century shipwreck washed ashore in the Cape Ray area of Newfoundland. Experts say stronger storms are one of the factors leading to more shipwreck finds.

President Vladimir V. Putin of Russia at the Kremlin on Wednesday. He said on Saturday that security measures were being tightened across the country.

Emergency services on Saturday at the Crocus City Hall concert venue outside Moscow after an attack there on Friday.

Smoke rising above the Crocus City Hall concert venue after it was attacked on Friday night.

People gathered in 2009 outside a theater in Moscow for the seventh anniversary of its seizure by Chechen gunmen, who held hundreds of people hostage for days.

Smoke from the burning Crocus City Hall concert venue in Moscow after a major attack on Friday.

The World Artificial Intelligence Conference in Shanghai in July 2023. China has invested heavily in A.I. education.

Students visiting Gunung Padang last year in Cianjur, Indonesia.