Videos showed fireballs over a facility in Ryazan, 110 miles southeast of Moscow. Kyiv is seeking to disrupt Russian military logistics and put pressure on the country’s economy by striking its oil industry.

Ukraine is using unmanned aircraft carrying explosive warheads as part of a campaign of long-range drone attacks, aiming to inflict blows on Russia far behind the front line. Kyiv's military granted Reuters exclusive access during the launch of the drones.

North Korea is likely preparing to send additional troops to Russia after suffering heavy losses in battles against Ukrainian forces, South Korea's military said Friday.

North Korea and Russia's deepening military relationship has sounded alarm in South Korea and the United States.

Kim Jong Un's soldiers have joined the Russians in the war against Ukraine. Although North Korean military personnel are dying in large numbers in the battles, they have developed a method for destroying Ukrainian drones.