A passenger bus has been hit by a shell near a military checkpoint in eastern Ukraine, killing at least 11 civilians and wounding several others.
Among the dead are six women and a teenager.
Regional authorities loyal to Kiev say the bus had been passing a Ukrainian army checkpoint, putting it in the line of fire.
Leonid Matyukhin is the spokesperson for Ukraine's Anti-Terrorist Operation.
"At 1415, the checkpoint near Volnovakha was under shelling from Dokuchaivsk town, controlled by terrorists. As a result, a civilian bus, on its way from Zlatoustovka to Donetsk, was destroyed."
Bus routes in the area have now been suspended.
Rebels in eastern Ukraine have denied responsibility for the incident.
Ukrainian President Petro Poroshenko has condemned the attack.
"Today's terrible tragedy near Volnovakha belongs to the events that stand out due to their cruelty even under strict standards of modern times. These events give the creeps."
Poroshenko says he will sign a decree later today on the next wave of mobilization against the rebels.
The incident is likely to deal the final blow to hopes that a short-lived and shaky cease-fire could take hold.
Diplomacy to end the conflict has also suffered a setback.
A multilateral summit among leaders from Ukraine, Russia, Germany and France over the situation in eastern Ukraine has already been called off.
The meeting, originally planned for Thursday in Kazakhstan, was aimed at signing a peace document between Kiev and Moscow.
