A ceasefire between Ukraine’s army and pro-Russian rebels in the east has come into effect, though sporadic shelling was reported in some places.
Both sides ordered their forces to stop fighting from midnight local time (22:00 GMT Saturday).
According to a BBC report, however, the two sides later traded accusations over reported artillery and mortar fire.
Fighting had raged near the besieged strategic town Debaltseve just hours before the truce, agreed by leaders this week in Minsk, was due to kick in.
Ukrainian President Petro Poroshenko, Russian President Vladimir Putin, French President Francois Hollande and German Chancellor Angela Merkel brokered the agreement on Thursday after marathon talks in the Belarusian capital.
Officials say more than 5,400 people have been killed since the conflict erupted in eastern Ukraine in April, but the UN believes the actual death toll to be much higher.
The fighting followed the annexation by Russia of Ukraine’s southern Crimea peninsula.
Ukraine and the West accuse Russia of sending troops and weapons to help the separatists in Ukraine’s eastern Donetsk and Luhansk regions – a claim the Kremlin vehemently denies.
Ukrainian military spokesman Vladyslav Seleznyov said army positions in the town of Popasna and near the villages of Zolote and Chernukhyno were fired on after the ceasefire.
In all, there were 10 shelling incidents, Valeriy Chalyi, a senior official in the Ukrainian presidency, told the BBC.
However, Mr Chalyi added that they did not have “a significant impact” on the truce.