Ukraine crisis: Russia warns on EU sanctions as truce holds
Russia has vowed to respond if the European Union imposes new sanctions over the Ukraine crisis.
The EU says the sanctions, targeting more Russian individuals, will come in on Monday but could be later suspended if Russia withdraws troops from eastern Ukraine and observes a current truce.
Friday's ceasefire appears to be largely holding - but there were reports of shootings by both sides.
Some 2,600 people have died since a pro-Russian rebellion began in April.
'Party of war'
The Russian foreign ministry said in a statement: "As for the new list of sanctions from the European Union, if they are passed, there will undoubtedly be a reaction from our side."
The fresh sanctions would add another 24 people to the list of people barred from entering the EU and whose assets have been frozen.
Among them would be the rebel leadership in the eastern Donetsk and Luhansk regions, officials in Crimea, which was annexed by Russia in March, and Russian "decision-makers and oligarchs", European Council President Herman Van Rompuy and European Commission chief Jose Manuel Barroso said in a statement.
Analysis: BBC business correspondent Theo Leggett
The new sanctions are intended to ramp up economic pressure on Russia. They are designed to make it much harder for state-owned energy and defence companies to borrow money on European financial markets, building on existing measures which target Russian banks.
A ban on selling so-called dual use goods, such as machinery or computing equipment which can be used for both civilian and military purposes is to be extended, while a further 24 people will be added to a list of individuals who are banned from travel within Europe and whose assets in the region are frozen.
The Russian foreign ministry said the EU was "practically sending a signal of direct support to the 'party of war' in Kiev".
Its statement added: "Instead of feverishly searching for ways to hurt the economies of its own countries and Russia, the European Union would do better to work on supporting the economic revival of the Donbas region."
There were no reports of major fighting in the east overnight.
However, the spokesman for Ukraine's National Security and Defence Council, Andriy Lysenko, said the rebels had fired 10 times on Ukrainian troops since the truce.
Unconfirmed reports also say a number of fighters from Ukraine's Aydar battalion were ambushed and killed after the ceasefire.
The BBC's Richard Galpin in Donetsk said he had not heard any of the heavy artillery barrages that took place before the truce while the BBC's Fergal Keane tweeted from Mariupol, further south, that the ceasefire was holding there.
A BBC crew that travelled to Donetsk airport on Saturday morning heard a few gunshots and small explosions but residents said the night had been quiet.
Meanwhile, the rebel leader of the self-proclaimed Donetsk People's Republic, Aleksandr Zakharchenko, said the truce was "not being fully observed".
Under the terms of the ceasefire, both sides pledge to withdraw heavy weapons from the eastern battlefields as soon as possible.
Russia also agreed with Ukraine to restart humanitarian assistance to the eastern region.
Ukrainian President Petro Poroshenko said the deal was based on a 12-point peace plan that included the release of "hostages".
He said there should also be talks about a long-term solution to the conflict.
Ukrainian forces had until recently been making gains against the rebels but in the past few weeks the pro-Russian fighters have struck back.
Ukraine and the West reported military columns crossing from the Russian border.
Meanwhile, Malaysian PM Najib Razak said he wanted to send a search team to eastern Ukraine "before winter sets in" to gather evidence about the downing of Malaysia Airlines Flight MH17.
A total of 298 people died when the plane came down over eastern Ukraine on 17 July, amid reports it was shot down by pro-Russian rebels.
Mr Najib called it an "atrocious crime".