Shelling in the recently recaptured Ukrainian city of Kherson killed at least 10 people Saturday morning, hours after President Volodymyr Zelenskyy of Ukraine warned that another wave of Russian strikes could mar the Christmas holidays.

"With the approaching holiday season, Russian terrorists may become active again,” Zelenskyy said in his overnight address. "Therefore, please heed the air raid signals, help each other and always take care of each other.”

His comments came after the Ukrainian military warned on Friday that Russian ships carrying cruise missiles had entered the Black Sea for the first time since Dec. 16, when Moscow fired a barrage of missiles across Ukraine.