Monday Briefing

A hardware superstore was hit in Kharkiv, Ukraine, on Saturday.Credit…Finbarr O’Reilly for The New York Times

Zelensky warned of a new Russian offensive

A day after a Russian missile strike on a hardware superstore in Kharkiv, Ukraine, killed at least 16 people, according to officials there, its president, Volodymyr Zelensky, said that Moscow’s forces were massing for a new ground offensive in the northeast.

Kharkiv has seen a sharp escalation in the ferocity of aerial attacks this month, forcing many to flee. On Saturday, a second strike, which came just hours after the attack on the superstore, hit commercial infrastructure, wounding at least 25 people.

Far from the front lines, U.S. and allied intelligence officials are tracking an increase in low-level sabotage operations in Europe, saying that the acts are part of a Russian campaign to undermine support for Ukraine.

The covert operations have mostly been arsons or attempted arsons targeting a wide range of sites, including a warehouse in England, a paint factory in Poland, homes in Latvia and an Ikea store in Lithuania. People accused of being Russian operatives have also been arrested on charges of plotting attacks on U.S. military bases.

Analysis: Vladimir Putin, Russia’s president, changed defense ministers this month for the first time in more than a decade, and he recently allowed corruption arrests among top officials. The purge is most likely a sign that he has greater confidence about his battlefield prospects in Ukraine.