Russian forces fired missiles at several cities in Ukraine and landed troops on its south coast on Thursday, officials and media said, after President Vladimir Putin authorized what he called a special military operation in the east, according the Reuters

Shortly after Putin spoke in a televised address on Russian state TV, explosions could be heard in the pre-dawn quiet of the Ukrainian capital of Kyiv. Gunfire rattled near the capital’s main airport, the Interfax news agency said, and sirens were heard over the city.

“Putin has just launched a full-scale invasion of Ukraine. Peaceful Ukrainian cities are under strikes,” Ukrainian Foreign Minister Dmytro Kuleba said on Twitter. “This is a war of aggression. Ukraine will defend itself and will win. The world can and must stop Putin. The time to act is now.”

U.S. President Joe Biden, reacting to an invasion the United States had been predicting for weeks, said his prayers were with the people of Ukraine “as they suffer an unprovoked and unjustified attack by Russian military forces”.

The full scope of the Russian military operation was not immediately clear but Putin said: “Our plans do not include the occupation of Ukrainian territories. We are not going to impose anything by force.”

Ukrainian President Volodymyr Zelenskiy said Russia had carried out missile strikes on Ukrainian infrastructure and border guards, and that explosions had been heard in many cities. Media reported that military command centres in Kyiv and the city of Kharkiv in the northeast had been struck by missiles while Russian troops had landed in the southern port cities of Odessa and Mariupol.

Global stocks and U.S. bond yields dived on Thursday, while the dollar, gold and oil prices rocketed higher as Russian forces fired missiles at several Ukrainian cities and landed troops on its south coast.