Donetsk: Fighting raged in Ukraine on Friday as the clock ticked down to a ceasefire that will be a first test of the commitment by Kiev and pro-Russian separatists to a freshly-inked peace plan.
At least 27 civilians and soldiers died in shelling as German Chancellor Angela Merkel warned Russia it risked fresh sanctions if the fighting did not stop.
With separatists fighting to conquer more territory ahead of the truce and Kiev forces digging in, there were also doubts about whether anyone would observe the midnight Sunday (2200 GMT Saturday) ceasefire vital to the success of the peace roadmap.
The fresh fighting came after rebels and Kiev agreed to the wide-ranging plan on Thursday after marathon talks in the Belarussian capital Minsk between the leaders of Russia, Ukraine, France and Germany.
Ukraine`s deputy defence minister Petro Mekhed accused the rebels of wanting to "raise their flag" over railway hub Debaltseve, scene of the bitterest recent fighting, and strategic port Mariupol ahead of the ceasefire.
"Ukraine is expecting an escalation and taking all necessary measures to be able to respond," Mekhed told journalists.
The fragile agreement was seen as the best hope of ending the conflict, which has killed at least 5,480 people and ratcheted East-West tensions to highs not seen since the Cold War, but scepticism remains high after the collapse of a similar previous peace plan.
Kiev and the West accuse Russia of stoking the war in ex-Soviet Ukraine by pouring arms and troops to help the pro-Russian rebels fighting Kiev government troops in Ukraine`s industrial east. Moscow denies the charges.
"I don`t want anyone to have any illusions or to seem like I`m naive -- there is still an awful long way to go to peace," Ukraine President Petro Poroshenko told troops near Kiev.
"Nobody is absolutely certain that the conditions for peace signed in Minsk will be fulfilled."
European Union foreign policy chief Federica Mogherini hailed the signing of the roadmap as "a first result".
"The first step is the ceasefire tomorrow evening and we`ll verify that on the ground," she said in Tunis.
Both sides are supposed to begin pulling back heavy weaponry from along the frontline no later than two day after that.
German Chancellor Angela Merkel, warned Russia that the EU, which has already slapped Moscow with sanctions over the crisis, was not ruling out further measures if the truce failed.
"If there are difficulties we wouldn`t rule out other sanctions," she said in Brussels on Thursday, after the 17-hour Minsk talks with French President Francois Hollande, Russian leader Vladimir Putin and Poroshenko.Ukraine`s military said that fighting remained fiercest around Debaltseve, with rebels firing missiles at the beleaguered railway hub mid-way between the main separatist bastions of Donetsk and Lugansk.
An AFP journalist in the rebel capital of Donetsk said that sporadic missile salvos and dozens of artillery bombardments could be heard around the city early Friday morning.
Kiev has accused Russia of deploying another 50 tanks across the border during the talks in Minsk.
The United States, which has said it could supply Ukraine with weapons if the conflict continues, cautiously welcomed the peace accord, but emphasised the work yet to be done in making it stick.
"The true test of today`s accord will be in its full and unambiguous implementation," the White House said, including "restoration of Ukrainian control over its border with Russia."
Rebel leaders -- seen by the West as Kremlin puppets -- have said that the new deal raises hopes of peace but warned there would be no more talking if it fails.The new Minsk agreement is broadly similar to an earlier failed deal in September, except that the new heavy weapons-free zone will be 50 to 140 kilometres (31-87 miles) wide, depending on the range of the weapon, double the width of the buffer zone agreed in September.
Kiev will also begin retaking control over the approximately 400-kilometre (250 mile) stretch of Russia`s border with rebel-held Ukraine, but only after local elections are held.
The border is entirely under Russian and pro-Russian rebel control and is used, according to Kiev, as a conduit for separatist supplies. The Kremlin denies this but has opposed Ukraine being allowed to regain control of the frontier.
Separatist-held territories will be granted a degree of autonomy to be established through talks, and the right to decide which language they use.