On Tuesday, Ukraine’s border service said 30 Ukrainian soldiers were injured in a battle with pro-Russians near the Russia-Ukraine border, a day after President Petro Poroshenko ordered troops to retake the border.

From Reuters:

It [border service] said separatist fighters had fired mortar bombs on government forces and border guards during the night near the city of Luhansk. It gave no details of any casualties among the rebels, who oppose central rule by Kiev’s pro-Western leaders.

The separatists say government forces have been shelling their positions this week, including around the city of Slaviansk, scene of some of the heaviest fighting since the uprising began in the Russian-speaking east in April.

Ukraine and the West accuse Russia of causing trouble in east Ukraine, but Moscow denies involvement. However, on June 12, Ukrainian Interior Minister Arsen Avakov said three Russian tanks crossed into Ukraine and Russian Foreign Minister Sergei Lavrov admitted Moscow provides “humanitarian” aid to the pro-Russians. Poroshenko wants the border secure and only then will he call for a ceasefire.

“The ceasefire will be declared as soon as the border is secure,” Poroshenko told his Security Council. “Declaring a ceasefire while the border is open would be irresponsible.”

On June 14, pro-Russians in Luhansk shot down a Ukrainian military plane and killed 49 servicemen. Overall, over 125 soldiers have been killed in east Ukraine since mid-April.