The shelling which hit the top-security prison in the separatist stronghold of Donetsk killed one inmate and injured several more, local authorities said Monday. The blasts hit living areas, offices and an electrical substation at the facility in the city's west on Sunday evening.

"A riot started in the facility and 106 people escaped their place of detention," a statement from Donetsk's city council said, adding that several of the would-be fugitives had been returned to the jail by Monday morning.

City council spokesman Maxim Rovensky, quoted by the AP news agency, said the prisoners on the run had been jailed for offenses including murder, rape and robbery.

City under fire

Rovensky added that at rocket fire overnight had hit at least 10 homes, shops and garages and that 20,000 people were living without electricity. A correspondent for the AFP news agency reported sporadic shelling into Monday morning. It follows repeated exchanges of rocket fire between separatists and Ukrainian government forces over the past few days, with a hospital, buses and residential buildings among those hit.

Ukrainian forces have surrounded Donetsk, which had a population of one million prior to the mass exodus of residents. A Ukrainian military spokesman on Monday said Kyiv's forces were getting ready to take the city from the pro-Russian separatists. Ukraine's military has already cut Donetsk off from the other main city held by separatists, Luhansk, on the Russian border.

"The forces of the 'anti-terrorist operation' are preparing for the final stage of liberating Donetsk. Our forces have completely cut Donetsk off from Luhansk. We are working for liberating both towns but it's better to liberate Donetsk first - it is more important," military spokesman Andriy Lysenko told the Reuters news agency.

The separatists proposed a ceasefire over the weekend to avert a humanitarian disaster. The request was greeted with apprehension from Ukraine's military and Western leaders, who voiced concerns it could be an attempt to allow Russian aid, or Russian soldiers, into the region.

The clashes between pro-Russia separatists and government troops in eastern Ukraine during the past four months have led to several thousand people fleeing their homes. According to the United Nations, more than 1,300 people have been killed.

se/kms (AP, AFP, Reuters)