Nearly 50 people were injured in a drone strike launched by Russia on Ukraine's second-largest city late Friday, officials said.

"Nearly 50 people have been wounded because of the massive attack by the invader" on four districts, Kharkiv governor Oleg Synegubov wrote on Telegram.

"Fires have broken out. Residential buildings, civilian infrastructure and cars have been damaged," in the drone strikes, he added.

Russian strikes hit 12 locations in four key districts of the city, Mayor Ihor Terekhov wrote in a post on Telegram.

Kharkiv, some 30 kilometers (19 miles) from the country's northeastern border, has remained a repeated target of Russian attacks since Russia's full-scale invasion of Ukraine in February 2022.

Hours before the attack in Kharkiv, Russia launched a strike in the southern city of Zaporizhzhia that wounded more than 20 people.

Attacks come ahead of ceasefire

President Volodymyr Zelenskyy decried the drone attack on Ukrainian cities and said the country's allies are slow in helping it improve its air defence capability.

"There were no military targets, nor could there be any. Russia strikes dwellings when Ukrainians are in their homes, when they are putting their children to bed," Zelenskyy wrote on Telegram.

Russia has announced a three-day ceasefire in Ukraine next week to coincide with commemorations in Moscow for the end of World War Two.

Kyiv has denounced it as a "manipulation" that is "just for a parade" that the Kremlin holds on Red Square every year.

Edited by: Sean Sinico