Ukraine army attacks eastern rebels as truce ends
Ukrainian forces have launched a full-scale military operation against pro-Russia separatists in the east, hours after a ceasefire ended.
Rebel bases and strongholds are under attack from aircraft and artillery.
The 10-day ceasefire ended on Monday evening, with President Petro Poroshenko saying "criminal elements" had thwarted the chance for peace.
Russia condemned Ukraine's operation, with President Vladimir Putin vowing to continue to protect ethnic Russians.
Ukraine's parliamentary Speaker Oleksander Turchynov told MPs on Tuesday: "I can inform you that in the morning the active phase of the anti-terrorist operation was renewed.
"Our armed forces are carrying out strikes on terrorist bases and checkpoints."
President Poroshenko went on television on Monday night saying: "We will attack, we will free our land."
The president had come under pressure from protesters in Kiev, who urged a renewal of the operation against the separatists.
Russia's foreign ministry condemned the Ukrainian operation, calling for a "real, not fake, ceasefire".
Mr Putin on Tuesday vowed he would continue to defend ethnic Russians abroad, using all means available from humanitarian aid to "self-defence".
"Under threat in Ukraine are our compatriots, Russian people, people who feel themselves part of the wider Russian world," he said.
Mr Putin accused Mr Poroshenko of issuing only ultimatums and said the West was using the Ukraine crisis to destabilise the whole region as part of a policy to "contain" Russia.
'Militants and marauders'
Both sides in Ukraine had accused each other of violating the truce, during which frequent clashes were reported.
One separatist leader in the east vowed to continue fighting until all Ukrainian troops had left.
The "prime minister" of the self-declared Luhansk People's Republic, Vasiliy Nikitin, told the Interfax news agency: "All calls for our fighters to lay down arms can only be discussed after Ukrainian troops withdraw."
A four-way teleconference on Monday between Mr Poroshenko, Mr Putin, French President Francois Hollande and German Chancellor Angela Merkel had raised hopes the truce would be renewed.
But Mr Poroshenko said in his address: "The decision not to continue the ceasefire is our answer to terrorists, militants and marauders."
Ukraine and some Western powers accuse Russia of arming the separatists - a claim Russia denies.
The trigger for the current crisis was whether Ukraine should lean more towards Russia or the EU.
The refusal of Mr Poroshenko's predecessor, Viktor Yanukovych, to sign an EU deal late last year - under pressure from Russia - led to protests in Kiev and his eventual overthrow.
Russia has since annexed Ukraine's Crimea region, and separatists in the east declared independence from Ukraine.
President Poroshenko signed a landmark EU trade pact last Friday.