The ceasefire between government and pro-Russian separatist forces has taken hold in eastern Ukraine. Western leaders have expressed skepticism that the temporary truce will lead to a long-term peace plan.
Ukrainian President Petro Poroshenko said he had ordered government forces to put down their weapons at 6 p.m. (1500 UTC) on Friday, after representatives from Ukraine, Russia and the Organization for Security and Cooperation in Europe (OSCE) signed a ceasefire agreement following talks in the Belarusian capital, Minsk.
The fighting appeared to have ceased after 6 p.m., although occasional shelling and explosions could still be heard near the separatist stronghold of Donetsk later in the evening.
Following the ceasefire announcement, negotiators continued to talk for two more hours to discuss the withdrawal of heavy weaponry from the restive region, the release of prisoners and the delivery of human aid to affected areas, Heidi Tagliavini of the OSCE told reporters in Minsk.
Poroshenko said the prisoners could be freed as early as Saturday. The release of the prisoners was part of 12 steps agreed to in the ceasefire deal, which will be overseen by OSCE monitors.
"We are expecting, in the very near future, the release of hostages, most probably it will happen tomorrow," Poroshenko told reporters on the sidelines of a NATO summit in Wales.
"The ceasefire will allow us to save not only civilian lives, but also the lives of the people who took up arms in order to defend their land and ideals," said the rebel leader from the Donetsk region, Alexander Zakharchenko.
In around five months of fighting, nearly 2,600 have been killed and hundreds of thousands have fled their homes since fighting began in eastern Ukraine, according to UN estimates.
"Human life is the highest value. We must do everything possible to end the bloodshed and put an end to people's suffering," Poroshenko said in a statement announcing the truce.
The Kremlin welcomed news of the truce, which keeps large areas in the east under separatist control. The ceasefire may help Russia avoid a new round of sanctions, which the European Union ordered to be prepared on Friday.
US President Barack Obama expressed doubts that the truce would hold. "Obviously we are hopeful, but based on past experience also skeptical that in fact the separatists will follow through and the Russians will stop violating Ukraine's sovereignty and territorial integrity. So it has to be tested," he told a press conference at the NATO summit.
"We also send a strong message to Russia that actions have consequences," Obama added. "Today the United States and Europe are finalizing measures to deepen and broaden our sanctions across Russia's financial, energy and defense sectors."
NATO Secretary General Anders Fogh Rasmussen echoed Obama's skepticism over ceasefire, but said he hoped it would be the first step to a settlement.
The next "crucial step is to implement it in good faith … but so far so good," he said, adding he hoped it "could be the start of a constructive political process.
dr/mg (AP, AFP, Reuters, dpa)