The unmanned aircraft carrying explosive warheads are part of a Ukrainian campaign of long-range drone attacks that aim to inflict blows on Russia far behind the front line as Moscow's troops advance in the east.

Ukraine has intensified missile and drone strikes on Russia. Russian air defenses are stretched, prompting efforts to find other approaches to protect domestic targets.

(Reuters) -Moscow Mayor Sergei Sobyanin said early on Friday that air defence units had intercepted attacks by Ukrainian drones at four locations around the Russian capital. Sobyanin, writing on the Telegram messaging app,

Ukrainian drones struck various targets within Russia. Videos emerged online from locations such as Ryazan, where a refinery was targeted. People gathered nearby were initially admiring the effects, but the strike led to an explosion that caused a panicked rush among the onlookers.