Separatist rebels fired on Ukrainian positions nearly 50 times in the past 24 hours and Russia is sending more tanks into Ukraine despite a cease-fire that was supposed to take effect five days ago, a Ukrainian military spokesman said Friday.

The report, which came a day after the Russian-backed rebels captured the key rail hub of Debaltseve, raises the question of whether weeks of high-level diplomacy aimed at producing a cease-fire and peace plan for eastern Ukraine simply allowed the rebels to redouble efforts to grab more territory.

The village of Kurakhovo, west of the rebel stronghold of Donetsk, was hit by fire from Grad rockets and the village of Berdyansk, near the key port city of Mariupol, was hit overnight by artillery and mortar fire, Lt. Col. Anatoliy Stelmakh said Friday.

He said Russia was still moving military equipment into Ukraine, including 10 tanks brought into Novoazovsk, near Mariupol.

Concerns have risen that the rebels are still gunning to take Mariupol, a government-held city on the Sea of Azov between mainland Russia and the Crimean Peninsula, which Russia annexed last March.  Taking the city could allow the rebels to create a land bridge between Russia and Crimea, which now have no direct links.

On Thursday, the rebels celebrated their victory over Ukrainian forces in Debaltseve, a key transport hub linking the two largest rebel strongholds. Rebel fighters roamed the town's debris-littered streets, laughing, hugging and posing for photos, although the death of one fighter when his vehicle hit a land mine was a reminder of dangers still lurking.

Ukrainian soldiers who made it out of Debaltseve alive on Thursday described weeks of harrowing rebel shelling, followed by a chaotic, hasty retreat. Ukrainian officials said 13 soldiers had been killed, 157 wounded in the fighting, with 90 taken prisoner and 82 missing -- but the shell-shocked soldiers themselves spoke of many more casualties.

"Starting at night, they would fire at us just to stop us from sleeping. They did this all night," a Ukrainian soldier named Andrei said Thursday after fleeing Debaltseve. "Then in the morning, they would attack, wave after wave. They did this constantly for three weeks."

The war in eastern Ukraine has killed more than 5,600 people and forced over a million to flee their homes since fighting began in April, a month after Russia annexed Crimea. Russia denies arming the rebels or supplying fighters, but Western nations and NATO point to satellite pictures of Russian military equipment in eastern Ukraine.

French and German leaders, who oversaw marathon peace talks last week between the presidents of Russia and Ukraine, signaled Thursday they were determined to salvage the cease-fire agreement and keep the two sides talking despite the fall of Debaltseve.

In Kiev, nationalists criticized the government for allowing the town to fall and not supporting its defenders enough.