All Big Four accounting and consultancy firms quit Russia.

Ukrainian filmmaker and activist Oleh Sentsov has been appointed commander of a battalion in the Armed Forces of Ukraine, Interfax-Ukraine reported on Sept. 13.

Czech helicopters arrived in Poland on Sept. 14 to reinforce NATO’s eastern defenses following a Russian drone incursion into Polish airspace a few days prior, the Polish Armed Forces reported.

Ukrainian special forces successfully detected and destroyed a Russian Buk-M3 anti-aircraft missile system in the occupied part of Zaporizhzhia Oblast on Sept. 14, Ukraine's military intelligence agency (HUR) reported.

Since the start of Russia's all-out war in February 2022, Estonia has provided over 500 million euros ($527 million) in military aid to Ukraine, amounting to 1.4% of the country's GDP.

The General Staff confirmed to Suspilne that train traffic was suspended following the detonation of munitions on a train carrying military supplies. The cause of the explosion will be established through an investigation.

The Metafrax Chemicals plant in Gubakha, Perm Krai, is subject to international sanctions by the U.K. and Ukraine.

In the latest episode of Ukraine This Week, the Kyiv Independent’s Anna Belokur breaks down Russia’s largest drone and missile attack on Ukraine, as well as the shocking incursion of Russian drones into Poland, which marked the first direct NATO engagement with Moscow since the full-scale invasion began.

"These railway lines are critical supply routes for Russian forces operating in the Kharkiv and Sumy directions," a source in Ukraine’s military intelligence told the Kyiv Independent.

The drone crossed into Romania on Sept. 13 during a Russian attack on Ukraine, penetrating about 10 kilometers (six miles) and remaining in NATO airspace for around 50 minutes, President Volodymyr Zelensky said.

The Kirishi refinery is one of the largest in Russia and has a processing capacity of over 17 million tons of oil per year. A fire broke out at the facility during a Ukrainian drone attack, Leningrad Oblast Governor Alexander Drozdenko claimed.

Ukrainian forces downed 52 out of the 58 drones, including Shahed-type attack drones, launched by Russia overnight, the Air Force reported. Russia also launched an Iskander-M/KN-23 ballistic missile.