(AFP) - The Ukrainian Air Force announced Monday that it had shot down 13 explosive drones that took off from southern Russia at night, after sirens sounded for hours in Kiev.

The Air Force said on the Telegram application that Russian forces launched 15 Iranian-made Shahed aircraft from the Bryansk region, northeast of Kiev, 13 of which were shot down by Ukrainian forces.

Since October, Russia has launched missile and drone attacks targeting vital Ukrainian infrastructure, prompting Kiev to strengthen its air defenses with help from the West.

In Kiev, sirens sounded for hours early Monday warning of air strikes, and authorities said air defenses had been activated by an "air target".

The official of the military administration, Sergei Popko, said that the marches were on their way to Kiev, but the Ukrainian air defenses shot them down and did not cause human casualties or affect infrastructure.

Ukraine has strengthened its ability to counter Russian air strikes after receiving new missile defense systems from Western allies such as the United States and Britain.

Despite this, a march attack in late February killed two people and wounded three others in the city of Khmelnytskyi in western Ukraine.

Last month, Washington announced an additional $2 billion in security assistance to Kiev, after agreeing in December to deliver the high-performance Patriot missile defense system.

And AFP correspondents recently saw elements of the Ukrainian forces on the outskirts of Kiev, protecting them from marching attacks with machine guns dating back to the period before the Second World War.