AKIPRESS.COM - Ukraine's government and separatist rebels have failed to begin withdrawing heavy weapons from the front line, despite a Monday deadline.

The two sides were given until two days after the latest truce came into effect to start the pullout.

Although most areas are quiet, fierce fighting is reported inside the town of Debaltseve, a key transport hub.

The leaders of Germany, Ukraine and Russia discussed the crisis in an overnight phone call.

Germany said they had agreed "concrete measures" for observers to have greater access, but gave no details.

Observers from the Organisation for Security and Co-operation in Europe (OSCE), who are charged with monitoring the ceasefire, have been trying to reach Debaltseve after being denied access by pro-Russian rebels on Sunday.

Ukraine's military said on Tuesday that five soldiers had been killed and 14 wounded in the past 24 hours. A spokesman told AFP news agency that most of the deaths happened near Debaltseve.

"The German chancellor and Ukrainian president called on the Russian president to exercise his influence on the separatists to enforce the ceasefire," German government spokesman Steffen Seibert said.