KYIV, Ukraine (AP) — Several loud explosions rocked the center of the Ukrainian capital Monday, a week after Russia orchestrated a massive, coordinated air strike across the country.

Kyiv city mayor Vitaliy Klichko said the central Shevchenko district of the capital had been hit, and urged residents to take shelter. No further details were immediately known.

The explosions came from the same central Kyiv district where a week ago a missile struck a children’s playground and intersection near the Kyiv National University’s main buildings.

Social media posts showed a fire in the area of the apparently strike, with black smoke rising into the early morning light.

Russian forces struck Kyiv with Iranian Shahed drones, wrote Andrii Yermak, the head of the Ukrainian president’s office, in a post on the Telegram social media site. Russia has repeatedly been using the so-called suicide drones in recent weeks to target urban centers and infrastructure, including power stations.

The strike on Kyiv comes as fighting has intensified in the eastern regions of Donetsk and Luhansk in recent days, as well as the continued Ukrainian counteroffensive in the south near Kherson and Zaporizhzhia. President Volodymyr Zelenskyy said last night in his evening address that there was heavy fighting around the cities of Bakhmut and Soledar in the Donetsk region. The Donetsk and Luhansk regions make up the bulk of the industrial east known as the Donbas, and were two of four regions annexed by Russia in September in defiance of international law.

On Sunday, the Russian-backed regime in the Donetsk region said Ukraine had shelled its central administrative building in a direct hit. No casualties were reported.