Four monitors for the Organization for Security and Cooperation in Europe (OSCE) who were abducted in May by pro-Russian gunmen in eastern Ukraine have been freed.
A leader of the pro-Russian separatists in the Donetsk region said the four had arrived at a hotel in the city of Donetsk.
Aleksandr Borodai said the four OSCE monitors had been held by a rebel leader in the neighboring restive region of Luhansk.
Borodai said the release was a goodwill gesture.
It comes as a weeklong truce that has failed to halt the fighting in eastern Ukraine is due to end later on June 27.
An OSCE official in Kyiv confirmed the four had been freed, noting they had "been absent for 31 days."
Mark Etherington also expressed concern over the fate of a further four OSCE monitors who were allegedly abducted by pro-Russian separatists in eastern Ukraine on May 29.
According to the AFP news agency, the four freed OSCE observers -- from Switzerland, Turkey, Estonia, and Denmark -- appeared tired and tense and they declined to speak to journalists in Donetsk.
Later on June 27, European Union leaders are due to discuss whether to impose further sanctions on Russia.
On the eve of the Brussels summit, U.S. Secretary of State John Kerry called on Russia to take steps to disarm separatists in Ukraine within "the next hours."
The U.S. State Department on June 25 said it had new Russia sanctions "ready to go," but Kerry said the United States would prefer not to be in "sanctions mode" and wanted Russia to take action without pressure.
On June 26, Ukrainian President Petro Poroshenko called on Russia to support his peace plan "with deeds, not words."
Addressing the Council of Europe's Parliamentary Assembly in Strasbourg, Poroshenko said he will make "a very tough decision" if the cease-fire is not extended.
Earlier, separatists in eastern Ukraine said they had agreed to fresh talks with Kyiv.
Former Ukrainian President Leonid Kuchma, representing Kyiv in the negotiations, confirmed another round would take place on June 27.
Russian President Vladimir Putin again said on June 26 that the cease-fire should be extended, and pointed to the growing number of people crossing into Russia from Ukraine.
According to the AP news agency, thousands of Ukrainians in cars stuffed with belongings lined up at the border to cross into Russia as the shaky cease-fire entered its final hours on June 26.
Meanwhile, separatists in Luhansk and Donetsk announced on June 26 that they have elected Oleh Tsaryov as speaker of a new unelected parliament uniting the unrecognized people's republics of the two Ukrainian regions.
According to Interfax, the two regions also announced they would form a confederation called the "union of people's republics."