On the Crimean peninsula, annexed by Russia, the Russian anti-aircraft guns have allegedly shot down drones in two strategically important locations.
There was a defense against air raids on Thursday evening at Crimea's largest military airfield, Belbek near Sevastopol, as local governor Mikhail Rasvozhayev announced.
Anti-aircraft fire and explosions could also be heard over the city of Kerch.
A drone was also allegedly shot down there.
At Kerch, the strategically important road and rail bridge connects the Crimea with the Russian mainland.
In the Russian region of Belgorod, an ammunition depot caught fire near the border with Ukraine.
The incidents far behind the actual frontline came just hours after a tripartite summit of Ukraine, the United Nations and Turkey in Lviv (Lemberg).
There, UN Secretary-General António Guterres and Turkish Head of State Recep Tayyip Erdogan discussed with Ukrainian President Volodymyr Zelenskyy whether talks about an end to the war that had been going on for six months were possible.
Zelenskyy reiterated that negotiations would only be possible once Russia had evacuated all illegally occupied areas in Ukraine.
Despite mediation efforts, the situation in and around the Zaporizhia nuclear power plant, which was occupied by Russian troops, continued to deteriorate.
Russia and Ukraine have accused each other of planning an attack there on Friday.
Guterres wanted to visit the southern Ukrainian port city of Odessa on the Black Sea on Friday and see how grain exports from Ukraine, negotiated with UN help, are going.
For Ukraine it is the 177th day of the war.
Russian military installations in Crimea no longer safe
The Ukrainian army has the right to destroy Russian military facilities in Crimea, said Presidential Advisor Mykhailo Podoliak on television.
The Kiev leadership has not officially claimed responsibility for the growing number of explosions and incidents in Crimea.
At the same time, it is clear that Ukraine is putting pressure on the Russian army on the hitherto untouchable peninsula, which serves as a military staging area.
After the explosions of the past few days, another column of black smoke was observed on Thursday afternoon in western Crimea near Mezhvodnoje.
The local civil defense spoke of burning grass.
According to Governor Raswoschajew, there was no damage or injury from the downed drone at Belbek Air Base.
The reports were initially not independently verifiable.
After the events, there was an air alert over the entire Ukraine on Friday night.
Is there a threat of an attack at the Zaporizhia nuclear power plant?
The Russian Defense Ministry and the Ukrainian military intelligence service issued ominous warnings on Thursday that the other side was planning acts of sabotage at the Zaporizhia nuclear power plant on Friday.
The Russian occupiers had unexpectedly announced a day off at Europe's largest nuclear power plant, the Kiev statement said.
Only the operating team should remain in the nuclear power plant, everyone else was forbidden to enter.
An unverified video has been circulating on the Internet, allegedly showing Russian military trucks in a hall next to a reactor.
The plant has been repeatedly shelled in recent days, for which the Russians and Ukrainians blame each other.
Zelenskyy spoke with Guterres in Lviv about an expected mission of international experts.
He sees no "objective obstacles" for International Atomic Energy Agency (IAEA) specialists to get to the power plant, he said.
The journey will lead "very quickly and safely on the legal route through the free territory of our state to the station".
The Russian troops must evacuate the nuclear power plant immediately and unconditionally, Zelenskyj demanded.
"The world has the power to enforce this." Otherwise one could forget all international legal acts on nuclear and radiation safety.
"Russia is destroying this international order."
Guterres again advocated demilitarization of the power plant and its surroundings.
Russia, on the other hand, is demanding that the experts travel through its territory and is refusing to withdraw its soldiers for alleged security reasons.
Estonia is sending more weapons to Ukraine
Estonia wants to supply Ukraine with more weapons, including mortars and anti-tank weapons.
That was decided by the government in Tallinn.
The Baltic EU and NATO country also wants to support Great Britain's initiative to train Ukrainian soldiers.
Estonia also wants to send another field hospital to Ukraine with Germany.
The small country says it has given Ukraine military aid worth 250 million euros since the Russian attack.
Large European countries such as Germany, France or Italy no longer announced any significant military or financial aid in July.
This was announced by the Kiel Institute for the World Economy, which is constantly evaluating all commitments.
"In July, the donor countries mainly delivered what they had promised and launched few initiatives for new aid," says the expert Christoph Trebesch.
According to a report by "Welt" (Friday), Ukraine has been asking Germany for new weapons for ten weeks in vain.
Russian President Vladimir Putin meets with Kazakh leader Kassym-Jomart Tokayev in Sochi.
Resource-rich Kazakhstan in Central Asia is an ally of Russia.
When it comes to the war against Ukraine, however, Kazakhstan is very careful to keep its distance from Moscow.