At least three persons were killed after Russia attacked Ukrainian capital of Kyiv with a series of drone strikes on Monday morning, Al Jazeera reported.

The attack came exactly one week after Russia launched a salvo of missile strikes across Ukraine. It was one of the severest strikes in the war that started on February 24.

Several buildings, including residential areas, were hit by the drones on Monday, the Associated Press reported. Kyiv city mayor Vitali Klichko urged residents to take shelter as the central Shevchenko district of the capital was hit.

In Kyiv region, 13 or more drones were shot down, said Yurii Ihnat, a spokesperson for the Ukrainian Air Force. Klitschko said 18 residents were rescued from the rubble of one apartment building but two others are still trapped under the debris.

The deputy head of the Ukraine president’s office, Kyrylo Tymoshenko, alleged that Iran-made Kamikaze drones were used in the attacks. These drones fly to their target and detonate. Iran, however, has denied supplying Russia with weapons for the war.

“We need more air defence systems and as soon as possible,” Ukrainian President Volodymyr Zelensky’s chief of staff, Andriy Yermak, said on social media on Monday. “More weapons to defend the sky and destroy the enemy.”

Zelenskyy criticised the attacks on civilians in Kyiv, with his office describing them as an act of desperation. “The enemy may attack our cities, but he cannot break us,” he wrote on Facebook. “Only fair punishment and condemnation of future generations awaits the invaders.”

Last week’s attacks killed at least 19 persons and injured 105, sparking an international outcry.

Russia claims its invasion of Ukraine is a special military operation that was necessary to prevent Kyiv from being used as a platform for Western aggression. But, Kyiv and its Western allies have dismissed these arguments as baseless pretext for a war.