Ukraine crisis: Rebels free hundreds of soldiers
Rebels in eastern Ukraine have freed 648 soldiers under the terms of the ceasefire with the government, the Ukrainian military has said.
Work was under way to free a further 500 soldiers, it added, clarifying a statement by President Petro Poroshenko on Monday that 1,200 had been freed.
The rebels say that 311 of their men remain in government captivity.
Officials insist a ceasefire agreed last week appears to be holding, despite several reports of clashes.
Russian Foreign Minister Sergei Lavrov said on Tuesday that the truce was being observed "in general".
Meanwhile, Ukrainian defence ministry spokesman Andriy Lysenko said the situation in the Donetsk and Luhansk regions remained tense.
He accused the rebels of violating agreements and shelling government forces' positions, while insisting that Ukrainian troops had only fired in response.
Mr Lysenko said that the ceasefire had activated the process for releasing prisoners, with 648 Ukrainians freed so far by the rebels, and work under way "to free about 500 more prisoners".
A rebel leader, Andrei Purgin, told Interfax news agency that a further 36 people would be exchanged on Tuesday.
Under the truce reached on Friday, all captives held by both sides are due to be released.
Five Ukrainian soldiers have reportedly been killed since the ceasefire deal last Friday.
Meanwhile, EU member states have agreed to impose a new package of sanctions against Moscow, to come into force in the coming days.
EU ambassadors are set to meet on Wednesday to discuss when the measures should be put in place. The timing is expected to depend on their assessment of whether the ceasefire is holding in eastern Ukraine.
Diplomats say the new package will target Russian oil companies Rosneft and Transneft and the petroleum unit of state gas monopoly Gazprom.
Their access to financial markets will be restricted - a serious matter for Rosneft, which last month asked the Russian government for a $42bn (£25.2bn) loan.
Russia has warned that it could block international flights through its airspace if the EU goes ahead with new measures.
On Monday, Mr Poroshenko visited the port city of Mariupol, which has been under attack from pro-Russian rebels.
Before the truce came into place, pro-Russian separatists made big gains in eastern Ukraine and seized territory a few miles outside Mariupol.
The ceasefire deal, aimed at ending five months of fighting, was reached in Minsk, Belarus, in talks brokered by the OSCE.
Mr Poroshenko appealed on Monday for the OSCE to send representatives to areas where the ceasefire has been broken.
Fighting in eastern Ukraine has left some 2,600 people dead since April.
12-point peace roadmap - key elements
- Ensure an immediate bilateral ceasefire
- Carry out decentralisation of power, allowing temporary local self-government in areas of Donetsk and Luhansk in eastern Ukraine under a "special status" law
- Immediately free all hostages and illegally detained persons
- Ensure monitoring on the Ukrainian-Russian border and a security zone
- Ensure the holding of snap local elections in Donetsk and Luhansk
- Remove illegal armed groups, military hardware, and all fighters and mercenaries from Ukrainian territory
- Pass a law against the prosecution and punishment of people over certain events in Donetsk and Luhansk region
Posted by the OSCE on its website (in Russian).