Ukrainian forces attacked the headquarters of the Russian Black Sea Fleet in Russian-held Sevastopol early on Sunday morning, according to the governor of the Crimean port city. At the same time, Ukraine claimed significant Russian attacks on two southern towns.

Russian media cited Sevastopol Governor Mikhail Razvozhayev as saying that five staff members were injured in the attack when a suspected drone flew into the headquarters' courtyard.

President Vladimir Putin commemorated Russia's Navy Day by declaring that the Russian navy would receive "formidable" hypersonic Zircon cruise missiles in the coming months. The speed of hypersonic weaponry is nine times that of sound.

He did not directly reference Ukraine.

Overnight and early Sunday morning, according to Ukrainian authorities, Mykolaiv and Nikopol, two cities in the country's southern region, were subjected to intense Russian airstrikes.

Mayor of Mykolaiv, Ukraine, Oleksandr Senkevych, informed Ukrainian media that two people were killed and three others were injured when 12 missiles struck residential areas and schools. Earlier, he described the strikes as "probably the most powerful" on the city during the entire war.

On Sunday morning, up to fifty Grad rockets struck residential neighborhoods in Nikopol, Dnipropetrovsk Governor Valentyn Reznichenko posted on Telegram. One individual was injured.

Reuters could not independently verify the battlefield accounts.

Putin dispatched tens of thousands of troops across the border on February 24, igniting a battle that killed thousands, displaced millions, and significantly strained relations between Russia and the West.

The most significant battle in Europe since World War II sparked an energy and food crisis roiling the global economy. Ukraine and Russia are both essential grain suppliers.

Harvest Could be Halved

Due to the invasion, President Volodymyr Zelensky stated on Sunday that this year's harvest could be half of what it usually is.

"Ukrainian harvest this year is under the threat to be twice less," Zelenskiy posted on Twitter, implying that it will be half as large as usual. "Our first objective is to prevent a global food disaster brought on by the Russian invasion. Still, grains find different delivery methods "he added.

Due to the fighting, it has been difficult for Ukraine to transport its goods to buyers through its Black Sea ports.

However, an agreement agreed by the United Nations and Turkey on July 22 guarantees safe passage for ships carrying grain out of three ports in southern Ukraine.

A spokesperson for Turkish President Recep Tayyip Erdogan stated on Sunday that it is likely that the first grain-exporting vessel will depart Ukraine's ports on Monday.

Eastern Danger

In a late Saturday night television address, Zelenskiy stated that hundreds of thousands of people were still exposed to intense warfare in the Donbas region, which includes the Donetsk and Luhansk provinces and which Russia intends to conquer. Before the invasion by separatists backed by Russia, large swaths of the Donbas were under the control of locals.

"Many refuse to leave but it still needs to be done," added Zelensky. "The more people leave the Donetsk region now, the fewer people the Russian army will have time to kill."

Sunday, Russia asked United Nations and Red Cross investigators to investigate the deaths of scores of Ukrainian detainees held by separatists backed by Russia.

Ukraine and Russia have traded allegations over a missile strike or explosion that killed dozens of Ukrainian prisoners of war in the front-line village of Olenivka in eastern Donetsk on Friday morning.

Russia has requested U.N. and Red Cross investigators to investigate the killings "in the interests of conducting an objective investigation," the defense ministry announced on Sunday.

The ministry issued a list of fifty Ukrainian prisoners of war dead and seventy-three wounded in what it claimed was a Ukrainian military attack with a High Mobility Artillery Rocket System manufactured in the United States (HIMARS).

The Ukrainian military denied culpability, claiming that Russian artillery had bombed the prison to conceal mistreatment.

Journalists from Reuters confirmed some of the killings at the prison but could not instantly validate the conflicting versions of events.

The United Nations has stated that it was willing to dispatch investigators provided it had authorization from both parties. The International Committee of the Red Cross noted that it sought access and offered assistance with evacuating the wounded.

Russia denies that its forces intentionally attacked civilians or committed war crimes during the invasion, which it refers to as a "special operation."

The Ukrainian military reported on Saturday that more than one hundred Russian soldiers had been killed and seven tanks destroyed in the south on Friday, including in the Kherson region, which is the epicenter of Kyiv's counteroffensive in that part of the country and a vital link in Moscow's supply lines.

The military's southern command stated that rail service to Kherson over the Dnipro River had been halted, potentially isolating Russian forces west of the river from supplies in occupied Crimea to the east.

Ukraine has employed Western-supplied long-range missile systems to severely damage three bridges over the Dnipro in recent weeks, isolating the city of Kherson and, according to British authorities, leaving Russia's 49th Army on the river's west bank highly exposed.

This week, officials from the administration assigned by Russia to govern the Kherson region disputed Western and Ukrainian assessments of the situation.