After weeks of warnings from the West and Ukraine, Russia launched an attack against the Eastern European country late Thursday under orders from President Vladimir Putin, who said it was the start of a “special military operation.”

Ukraine’s border guard service said in a statement that Russian troops, supported by Belarus’ military, began attacking northern border units with artillery, heavy equipment and small arms at about 5 a.m. local time from Belarus where they were stationed.

Attacks were also occurring in the eastern Ukrainian regions of Luhansk, Sumy, Kharkiv, Chernihiv and Zhytomyr, as well as in the southern Crimea Peninsula and in several western Ukrainian regions, officials said.