At least one person died after a series of large explosions on Tuesday at a Russian military air base in Crimea. Russia claims the explosions were caused by an accidental detonation of ammunition. Ukrainian officials have not publicly commented on the explosions, but an unnamed Ukrainian military official told The New York Times that pro-Ukrainian forces were behind the blast. In an address on Tuesday night, Ukrainian President Volodymyr Zelensky did not discuss what happened at the Russian air base, but he called for Crimea to be returned to Ukraine. Russia annexed Crimea in 2014.