AP PHOTOS: Day 31: Biden visits Poland, rockets hit Ukraine

As President Joe Biden visited Poland on Saturday and called for Western unity against the Russian invasion of Ukraine, rockets struck the western Ukrainian city of Lviv, sending waves of fear across a place that had been a refuge for hundreds of thousands of people fleeing attacks on other parts of the country.

In Lviv, the closest major Ukrainian city to Poland, thick black smoke could be seen coming from the first blast site for hours before a second set of explosions was heard. People sheltered underground after the explosions.

The explosions happened while Biden was in Poland’s capital, Warsaw, about 340 kilometers (210 miles) away. The images of the American president visiting Ukrainian refugees and humanitarian aid workers in Poland contrasted with images of flames shooting from blast sites and people huddled together in bomb shelters in Lviv.