Authorities say a Russian missile hit a Ukrainian army training ground in an attack that killed three soldiers and wounded 18 others.

It is the third Russian attack on a Ukrainian training unit in little more than two months. An Iskander missile attack on a camp in the norther border region of Sumy killed six servicemen in May and another strike killed 12 people and wounded another 60 last month.

The attack, just hours after President Trump gave the Kremlin a new deadline to work toward ending the war, was part of a wave across the country, the authorities said.