Russia has attacked Lviv. Here's why the western city is so important to Ukraine's defense

Russia launched missile strikes near an airport in Lviv on Friday, a strategic Ukrainian city not far from the Polish border that had until now largely been spared from the relentless bombardment witnessed across much of the country during the war.

Lviv mayor Andriy Sadovyi said several missiles hit an aircraft repair plant, but that work at the facility had stopped before the strikes and there were no reports of casualties.

Ukraine's armed forces say initial information suggests Russia launched six missiles towards the Lviv on Friday morning. It says the missiles were most likely air-launched cruise missiles fired from warplanes over the Black Sea.

Two of the six were intercepted by air defense systems, the armed forces' statement on Facebook said.

The attack will add to concerns that Russia's war could spread further west. Here's what you need to know about the importance of Lviv.