Ukraine’s Kyiv has come under attack for the first time in months, the city’s mayor has said, as large explosions were heard in the capital.

“Strong explosions were heard on the left bank of the capital,” Kyiv Mayor Vitali Klitschko said on Saturday in a post on the Telegram messaging app, referring to the left bank of the Dnipro river.

“Preliminary, air defence was working against ballistic (missiles).”

There were no immediate reports of casualties.

Two strong explosions were heard and trails were visible in the sky in central Kyiv on Saturday morning, AFP news agency reported, citing its journalists in the city.

Air alerts for Kyiv and a nearby region were announced just minutes before the explosions were heard, and city authorities urged residents to stay in shelters.

Saturday’s attacks were the first on Kyiv since September 21, when Ukrainian air defences downed a missile over the capital. Falling debris from the missile wounded seven people, including a child.

Ukrainian President Volodymyr Zelenskyy said earlier this week that Ukraine had deployed more Western air defence systems in anticipation of a second full winter of Russian attacks on energy facilities.

Russian attacks last year hit Ukraine’s energy grid, leaving thousands without heating or electricity in freezing temperatures.