Ukraine was swift to blame Russia. President Zelensky called it "a Russian missile attack on collective security" and as such "a very significant escalation".
Foreign Minister Dmytro Kuleba said it was "a conspiracy theory" to suggest missiles were part of Ukrainian air defences. These claims about Russia subsequently appear unfounded.
Baltic states on the front line with Russia were quick to call on the collective defence of Nato. "Every inch of NATO territory must be defended!"
Latvia's defence minister, Artis Pabriks, suggested NATO could provide more air defences for Poland and "part of territory of Ukraine".
Kaja Kallas, Estonia's prime minister, said the West should give Ukraine more military, humanitarian and financial support.
In contrast, the initial response from the United States and other Western countries was to call for calm and wait for the facts to emerge.
There was a clear desire to avoid any escalation that could involve a collective Nato military response.
American officials were among the first to suggest the missiles were part Ukrainian air defences.