Russia says unauthorized use of cellphone allowed Ukraine to target its soldiers

Unauthorized use of cell phones by Russian soldiers led to a deadly Ukrainian rocket attack on the facility where they were stationed, according to the Russian military, as it raised the death toll from the weekend attack to 89.

Gen. Lt. Sergei Sevryukov said in a statement late Tuesday that phone signals allowed Kyiv's forces to "determine the coordinates of the location of military personnel" and launch a strike. The Russian military is taking unspecified measures to "prevent similar tragic incidents in the future," Sevryukov said, and promised to punish officials responsible for the blunder.

The attack, one of the deadliest on the Kremlin's forces since the start of the war over 10 months ago, occurred one minute into the new year, according to Sevryukov.