Russian forces initiated six strikes on Kharkiv overnight, damaging civilian infrastructure, Ukrainian officials said early Thursday.

The mayor of Kyiv also said explosions occurred in the Ukrainian capital overnight. Debris from the downed rockets fell in the Darnytskyi and Holosiivskyi districts of the city.

Five people were hurt in the Darnytskyi district of Kyiv, where the strike also destroyed non-residential buildings. Three of them, including a 9-year-old girl, were hospitalized. Two were treated by medics on scene.

In the Shevchenkivskyi district of Kyiv, rocket debris damaged a gas pipe, an official said.

-ABC News' Will Gretsky

Seventeen people were killed, and 32 others injured, when a Russian missile hit a market in the center of Kostyantynivka in the Donetsk region, according to Ukrainian officials.

"At this moment, the artillery of Russian terrorists has killed 16 people in the city of Kostiantynivka, Donetsk region," President Volodymyr Zelenskyy said on Telegram. "A regular market. Shops. A pharmacy. People who did nothing wrong. Many wounded. Unfortunately, the number of casualties and the injured may rise."

Ukrainian President Volodymyr Zelenskyy visited troops at the front line near Bakhmut as Ukrainian forces continue to make ground in their counteroffensive, the president's office said Tuesday.

Zelenskyy, who was accompanied by commander of ground forces Col. Gen. Oleksandr Syrskyi, thanked soldiers for their service and presented them with awards, according to a video released by the office.

"I awarded the best warriors. And I thank everyone who fights for the sake of the state," Zelenskyy said.

Ukrainian defense forces continue to advance in the direction of Melitopol, according to the spokesman for Pavlo Kovalchuk, the general staff of the Armed Forces of Ukraine.

"They were successful in the direction of Robotyne - Novoprokopivka. They are entrenching at the achieved milestones," the spokesman said.

-ABC News' Will Gretsky

Cuban officials announced Monday that they have "detected" and are "working on the neutralization and dismantling of a human trafficking network that operates from Russia to incorporate Cuban citizens living there, and even some from Cuba, into the military forces participating in war operations in Ukraine."

"Attempts of this nature have been neutralized and criminal proceedings have been initiated against people involved in these activities," the Cuban Ministry of Foreign Affairs said in a statement.

The ministry noted that "Cuba has a firm and clear historical position against mercenarism and plays an active role in the United Nations in repudiation of this practice."

"Cuba is not part of the war in Ukraine," the ministry added. "It is acting and will act energetically against anyone, from the national territory, who participates in any form of human trafficking for the purpose of recruitment or mercenarism for Cuban citizens to use arms against any country."

-ABC News' Mara Valdes