Multiple people were killed or wounded Thursday in the largest attack on Lviv’s civilian infrastructure since Russia invaded Ukraine last year, destroying entire floors of a residential building that was struck and leaving the streets below covered in rubble.

Four were killed and nine others injured, Interior Minister Ihor Klymenko reported Thursday, as emergency service workers searched in the debris for more people trapped.

Ukraine’s President Volodymyr Zelensky posted a reaction on Telegram, saying, “Unfortunately, there are wounded and dead. My condolences to the relatives! There will definitely be a response to the enemy. A tangible one.”

Zelensky also posted drone footage that shows wrecked buildings from above.

Third and fourth floors of the struck building were ruined.

Ukraine’s air force reported it intercepted seven of the 10 Kalibr cruise missiles that Russia fired from Black Sea toward the western Ukrainian region of Lviv and its namesake city around 1 a.m. Thursday.

Mayor Andriy Sadovyi said around 60 apartments and 50 cars in the area of strike were damaged.

Sadovyi addressed residents in a video message, saying the attack was the largest on Lviv’s civilian infrastructure since the beginning of the full-scale invasion last year.

Hundreds of thousands of Ukrainian war refugees have sought safety in Lviv from other areas to the east.