Ukrainian President Petro Poroshenko has said his forces will find and destroy pro-Russian separatists who killed at least 19 soldiers in a single attack in the east of the country.

The soldiers were killed in an apparent rocket near the Russian border.

Officials in Kiev say the separatists used Grad missiles.

They say that that more than 90 other soldiers were wounded in the most deadly attack since the president ended a unilateral ceasefire last month.

“For every life of our soldiers, the militants will pay with tens and hundreds of their own,” President Poroshenko said.

“Not one terrorist will evade responsibility. Everybody will get what is coming to them,” he said in a statement posted on his website after an emergency meeting of security chiefs.

Ukrainian officials say the rebels fired a barrage of Grad rockets at troops in Zelenopillya, a village near the border.

Pro-Russian rebels say they “destroyed a column” of troops there.