Ukraine and Russia said their emergency-warning apps were hacked, triggering false nuclear-threat alerts in both countries and chemical-attack and street-fighting warnings in Kyiv.

Dirk Helbing, Gwendolyn Sasse, Ivan Katchanovski, Ronald Beiner, Maria Snegovaya and 1 more

Frankfurter Allgemeine Zeitung, Die Zeit, Der Spiegel and 6 more

Ukraine and Russia traded accusations over a temporary ceasefire in occupied Oleshky, as Kyiv alleged Russian forces used the pause to reinforce positions and move weapons.

Ronald Beiner, Ivan Katchanovski, Maria Snegovaya, Anne Applebaum, Klaus Adam

Russia-friendly Iliana Jotova won Bulgaria’s presidential runoff, defeating pro-Western challenger Andrey Gyurov and becoming the country’s first woman president in a low-turnout vote.

Pascal Delwit

Michigan Democratic Rep. Haley Stevens endorsed Republican Senate candidate Mike Rogers after losing her party’s primary to Abdul El-Sayed, drawing fierce backlash from Democrats.

Matthew Søberg Shugart, Barry C. Burden, Steve Peers, Robb Willer, Daniel W. Drezner and 53 more

A private jet bound for the Bahamas crashed near homes in South Florida on Sunday, killing all nine people aboard; the cause remained unclear.

Timothy D. McBride, Victor Asal