A series of explosions resounded throughout the Ukrainian capital Kyiv as air defence units engaged Russian drones, Reuters witnesses said.

“This is the sixth air attack on Kyiv since the start of the month,” said Serhiy Popko, head of the city’s military administration.

“Tonight, after three days of ballistic threats, the enemy again launched Shaheds on the capital. The drones attacked in groups, in waves, and from different directions,” Popko said.

There were no casualties and no major damage reported in Kyiv, Popko said.

The Ukrainian air force said the Russian military launched Iranian-made Shahed drones from three different directions in Russia targeting 11 different regions in the centre, north and south of the country. The air force said in a statement on the Telegram messaging app that fighter jets, anti-aircraft missile units and mobile fire groups of drone hunters repelled the Russian drone attack. Kyiv Mayor Vitali Klitschko said anti-aircraft units went into action as groups of the Russian drones flew across the outskirts of the city and targeted areas near the city centre.

Anti-aircraft activity was heavy, Klitschko said, in the Darnytskyi district on the east bank of the Dnipro and explosions also struck historic Podil on the opposite bank.

The Reuters witnesses reported loud blasts just after midnight. A new series of explosions over the next 45 minutes also hit areas near Kyiv’s central districts.

Overnight air alerts in many Ukraine regions lasted for about five hours.

Russian drone attacks on Ukrainian cities and regions have become increasingly frequent. Ukrainian officials have said Russia is targeting the nation’s power and energy infrastructure during and ahead of the critical cold months of winter.

Moscow has denied targeting Ukraine’s civilian infrastructure.