A Ukrainian drone attack struck deep inside Russia Monday, hitting the industrial city of Nizhnekamsk, 550 miles east of Moscow. The strike killed 13 people and injured 39 others in a sign of Ukraine’s escalation of the war deep inside Russian territory. The attack was the deadliest in Russia since the war began in February 2022, reflecting Ukraine’s ability to attack far beyond enemy lines.

Russian investigators said that a child was among those killed in the industrial city, which houses one of Russia’s largest oil refineries. The Uzbek consulate also counted among the dead seven Uzbek citizens. Thousands of Uzbeks work in Nizhnekamsk.

The Taneco oil refinery was also reportedly struck, igniting a fire at the facility.

Deaths among Russian civilians are still extremely low in comparison with Ukrainian civilian deaths, which number in the tens of thousands, as Russia has pounded civilian infrastructure in major Ukrainian cities and has targeted power plants that have left civilians without electricity and heating through difficult winters. Ukrainian strikes in Russia have triggered a fuel crisis, disrupted air travel, and caused internet shutdowns, with Ukraine hoping to pressure Russia into a ceasefire.

Ukraine remains vulnerable to airstrikes due to a worldwide shortage of Patriot missiles triggered by the war between Iran and the United States. Russia has taken advantage of this vulnerability to strike Kyiv and other major cities, killing hundreds of Ukrainian civilians over the summer.