LONDON — At least 100 people were injured and an undetermined number of others were killed in Ukraine as Russia struck the country with a “massive” drone and missile attack on Wednesday and into Thursday morning, Ukrainian President Volodymyr Zelenskyy said.

Russia launched almost 700 drones and 19 ballistic missiles, along with cruise missiles, Zelenskyy said. Ukraine shot down some 636 drones and “some” of the missiles, he said, adding, “Unfortunately, not all.”

“Tragically, there are fatalities in Odesa, Kyiv, and Dnipro,” Zelenskyy said in a social media post. “Among those killed is a boy — he was 12 years old. My condolences to the families and loved ones.”

This is a developing story. Please check back for updates.