Ukrainian President Volodymyr Zelenskyy thanked those "who oppose the occupiers" only hours after a military facility in occupied Crimea was hit by a series of explosions.
On Tuesday night, he urged Ukrainians to steer clear of Russian military bases and ammunition stores.
He added the explosions could have various causes, including incompetence.
"But they all mean the same thing — the destruction of the occupiers' logistics, their ammunition, military and other equipment, and command posts, saves the lives of our people," he said in an evening address.
The Russian Defense Ministry said sabotage was behind the explosions at the military depot in the Dzhankoy region of Crimea, the RIA news agency reported.
Kyiv has not formally confirmed responsibility but if Ukrainian forces were behind the explosions, it would demonstrate that they could carry out covert operations deep behind enemy lines.
Russia seized Crimea from Ukraine and then annexed the territory in 2014.
UN Chief the meet Zelenskyy and Erdogan in Ukraine
UN Secretary-General Antonio Guterres plans to travel to Ukraine on Thursday for a meeting with Ukrainian President Volodymyr Zelenskyy and Turkey's President Recep Tayyip Erdogan.
The leaders are expected to discuss a UN and Turkey brokered grain deal allowing Ukrainian food exports to be shipped to world markets to help alleviate the global hunger crisis.
"The need for a political solution'' to the war would also be raised during the meeting in the western city of Lviv, UN spokesman Stephane Dujarric said.
He added the three leaders will also discuss the situation at the Russian-controlled Zaporizhzhia nuclear power plant, where Russia and Ukraine have accused each other of shelling.
Guterres will also visit Odesa on Friday.
On Saturday, he will visit the center in Istanbul coordinating the Black Sea shipping, which includes the four parties to the deal — Ukraine, Russia, Turkey and the United Nations.
More on the war in Ukraine
DW's Miodrag Soric argues EU countries need to adopt a clear, consistent policy on visa bans for Russians.
Ukraine's nuclear operator, Energoatom, reported that Russian-based hackers launched a major three-hour attack on its website on Tuesday but had not caused significant problems. The cyberattack comes as tensions flare over the Zaporizhzhia nuclear power plant in southern Ukraine, which Russian forces occupied in March.
Chancellor Olaf Scholz said he was confident Finland and Sweden's NATO accession would progress rapidly. Sweden's Magdalena Andersson said the war in Ukraine had prompted major changes in Stockholm and Berlin alike.
The first humanitarian cargo of food from Ukraine since Russia's invasion has set off from Ukraine. The Lebanese-flagged cargo ship Brave Commander left Ukraine headed for the port of Djibouti carrying some 23,000 metric tons of wheat aboard, Ukraine's infrastructure ministry said.
