A shaky new truce in Ukraine has been put at risk on its second day after Kiev said persistent rebel attacks meant there was "no question" of it pulling back heavy weapons, and the European Union ratcheted up sanctions on Russia.

"There is no question at the moment of us withdrawing heavy weapons" from the frontline because of fire from pro-Russian separatists, a Ukrainian military spokesman, Vladyslav Seleznyov, told the AFP news agency.

Pulling back tanks, artillery and rockets from the frontline in Ukraine's east is scheduled to begin from midnight (22:00 GMT) on Monday as part of the second phase of a European-mediated truce agreed to last week.

But while monitors said the ceasefire that came into effect on Sunday was generally being followed, shelling was unabated around Debaltseve, a strategic railway hub linking the two main rebel-held cities of Donetsk and Luhansk. Monitors have not been able to reach Debaltseve.

Passage to Russia 

Al Jazeera's Charles Stratford, reporting from the rebel-held town of Uglegorsk, near Debaltseve, said incoming and outgoing shells had been heard following the ceasefire.

If the rebels were to fully take Debaltseve they would have a direct link to Russia, our correspondent said. 

The rebels said on Monday that they were prepared to provide a safety corridor in Debeltseve for Ukrainian soldiers, thousands of which were hold up in the hotspot town surrounded by pro-Russian rebels, and to set them free if they laid down their weapons, said Stratford.

 Clashes amid fragile ceasefire in Ukraine

Eduard Basurin, a rebel commander, told Reuters news agency: "We suggest that the Ukrainian soldiers in Debaltseve stay alive. There is just one condition: that they lay down their weapons. We didn't talk about them becoming prisoners. Lay down your weapons and get out of here."

Speaking to our correspondent on Sunday however, rebel leaders in Debeltseve said that they had no intention of laying down their weapons.

The Ukrainian government rejected the offer from the rebels later on Monday. 

Our correspondent said rebels say they do not include Debaltseve in the ceasefire deal. 

Maja Kocijancic, the European Commission spokeswoman, said in Brussels that "it is imperative the ceasefire is fully implemented... it means the shooting needs to stop".

The ceasefire was further tested as reports were confirmed late on Monday that clashes were ongoing between government and rebel groups in Shirokino, near Mariupol on the southeastern coast of the country.

'More than 100 attacks'

Ukraine's foreign minister, Pavlo Klimkin, said during a visit to Bulgaria that "the Ukraine armed forces are fully observing the ceasefire regime but unfortunately in response we have received 112... attacks in the past 24 hours from the terrorists of Donetsk and Luhansk".

Another military spokesman, Dmytro Chaly, told AFP that at least five Ukrainian soldiers had been killed and 22 wounded by rebel fire in the town of Shyrokine, near the coastal city of Mariupol, since the ceasefire started.

While tensions rose on the ground, the European Union upped the ante on the diplomatic front, adding two Russian deputy defence ministers, Anatoly Antonov and Arkady Bakhin, to its travel-ban and asset-freeze blacklist for allegedly sending Russian troops and material in to support the Ukrainian insurgency.

Three other Russians, including two lawmakers, and 14 Ukrainians acting as rebel military or political officials in the self-declared republics of Donetsk and Luhansk were also blacklisted, along with nine entities. The sanctions were agreed last month but put on hold while France and Germany worked to secure the ceasefire.

Russia denies repeated allegations that it is sending troops and tanks to support the pro-Russian rebels. The West, though, has imposed sanctions that, along with the sharp decline in oil prices, are accelerating the Russian economy's slide into recession.

Source: Al Jazeera And AFP