At least four explosions were heard near a major Russian military air base in the annexed Russian-occupied peninsula of Crimea on Thursday, local sources said.

The sources said the blasts were near the Belbek base, north of Sevastopol. However, a pro-Moscow official said no damage had been done.

The internationally non-recognized governor of Sevastopol said according to preliminary information, Russian anti-aircraft forces had downed a Ukrainian drone. He said no one was hurt and that there was no damage. 

Explosions were also reported around the Ukrainian city of Kerch, on the eastern edge of the Crimean Peninsula. 

Kerch is the gateway to a bridge — built in 2018 — that links Crimea with Russia. Ukraine has said the bridge is a legitimate target in its bid to force the Russian occupiers out of their lands.

Crimea was illegally annexed by Russia in 2014, and is an important supply route for Moscow's war in Ukraine. 

Earlier this week, Russia took the unusual step of admitting that saboteurs were responsible for orchestrating a series of explosions at an ammunition depot in Crimea on Tuesday. Last week, blasts ripped through a Crimean air base, which Moscow at the time said was caused by an accident.

Here's a roundup of some of the other key developments in Ukraine on August 18. 

Dawn shelling on city of Kharkiv

The governor of the Kharkiv Oblast, Oleh Synehubov, reported renewed dawn shelling of the city of Kharkiv on Thursday morning. 

"At the moment, there are 18 wounded, among them two children; one person died," Synehubov wrote on the Telegram social media network. 

Kharkiv came under Russian fire on Wednesday, too, with six people killed and 16 wounded in that attack according to the Ukrainian Emergencies Service.

President Volodymyr Zelenskyy called Wednesday's attack "a devious and cynical strike on civilians with no justification."  

Kharkiv, with a population of about 1.4 million according to UN figures from 2017, is situated close to the Russian border and has been contested for most of the war. It was also hit by artillery fire on Tuesday night. 

Finnish Defense Ministry suspects Russian jets violated airspace

Finland on Thursday said it suspected two Russian fighter jets had violated its airspace.

The Finnish Defense Ministry said the Russian MiG-31 fighter jets, which were headed west, were in the airspace on Thursday morning near the southern coastal city of Porvoo.

Defense communications chief Kristian Vakkuri told the news agency Reuters that the aircraft were in Finnish airspace for two minutes.

"The depth of the suspected violation into Finnish airspace was one kilometer," he said.

Moscow's Defense Ministry on Thursday was cited by the Russian news agency Interfax as saying it had relocated three MiG-31E warplanes equipped with Kinzhal hypersonic missiles to its Kaliningrad region.

Ukraine, Turkey, UN to hold talks in Lviv

Zelenskyy will meet with UN Secretary-General Antonio Guterres and Turkish President Recep Tayyip Erdogan later on Thursday in the western city of Lviv, far from the front lines. 

UN deputy spokesman Farhan Haq said that among other issues, Guterres would discuss "his overall efforts to do what he can to essentially lower the temperature as much as possible with the various authorities." 

Turkey, which helped broker an agreement clearing the way for Ukraine to export grain via the Black Sea, said the talks would also explore political solutions to the conflict. 

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Russia accuses Ukrainian forces of planning 'provocation'

Meanwhile, Russia's Defense Ministry said, without providing evidence, that Ukraine was planning a "provocation" at the Zaporizhzhia nuclear power plant to coincide with the UN visit. Shellfire has been reported at the Russian-controlled site repeatedly of late, with Ukraine and Russia blaming each other. Ukraine said on Wednesday that it would start nuclear disaster drills near the site.

Ukrainian presidential spokesman Oleksiy Arestovych said in a video message that the visit came amid "strategic deadlock" in the almost 6-month-old conflict. 

"Russian forces have achieved only minimal advances, and in some cases we have advanced, since last month," Arestovych said. 

Russia reports fire at ammunition depot in Belgorod region

Russian state-run Tass reports that an ammunition depot in the village of Timonovo caught fire. No casualties were reported though residents of Timonovo and nearby Soloti had to be evacuated, Belgorod regional governor Vyacheslav Gladkov said on Telegram.

Videos posted online showed huge dark plumes rising from the site of the purported ammunitions storage site.

"Operational services are working on the spot, the cause of the fire is being established," Gladkov said.

Timonovo has a population of 530 and 650 people reside in Soloti. The towns are located approximately 5.4 kilometers from the border with Ukraine.

Another food ship, this time carrying corn, sets sail

Turkey's Defense Ministry said on Thursday that another ship carrying Ukrainian food exports, corn this time, set sail in the Black Sea. 

The Belize-flagged "I Maria" set sail from the port of Chornomorsk, not far south of Odesa, from where many such ships have set sail. 

In total, 25 ships have left Ukraine under the UN-brokered deal, including three that departed on Wednesday. 

The war put additional pressure on already-rising food prices, with Ukraine and Russia both among the world's leading agricultural exporters. 

A separate UN deal sought to ensure Russian food and fertilizer exports would not be halted by roadblocks, in exchange for Russia's navy allowing ships safe passage.

Exiled activist says Russia recruiting soldiers from prisons

Russian prison rights activist and journalist Olga Romanova alleged on Thursday that Russia was looking to recruit soldiers from its prisons. 

Romanova claimed in a short Facebook post written in Russian that even prisoners who had not been convicted were being offered to have the charges against them dropped in exchange for signing up. 

She said she had heard of examples of this in pretrial detention centers near Moscow, but added "I think it has started everywhere."

Romanova moved to Germany in 2017 saying she feared persecution at home. 

Famously, Russia's conviction rate in criminal court cases has been consistent at around 99% for years, meaning very few defendants can hope to beat the charges in front of a judge or, much less frequently, a jury. 

ar, jsi, msh/sms (AFP, AP, dpa, Reuters)