Ukrainian police forces have freed the remaining hostages being held in a post office by a man believed to be strapped with explosives, and arrested the hostage taker after a standoff lasting several hours in the city of Kharkiv.
None of the hostages were harmed.
"All hostages freed in Kharkiv. The assailant was arrested," President Petro Poroshenko wrote on Twitter.
He praised the work of the Ukrainian security forces.
Interior Minister Arsen Avakov published a picture of the man, with blood streaming down his face, being held by a policeman.
Police had said earlier that the man had taken 11 people hostage.
Five of the hostages -- three women and two children -- were released following talks.
Regional police chief Oleh Bekh told reporters that the man had a history of antisocial behavior and drug-related offences.
"He probably needs the help of a psychiatrist," Bekh said. "During the detention, he received minor injuries. He was not in a normal state ... the hostages said he was drinking alcohol."
Police were able to enter the building after one of the hostages opened the door for them, Kharkiv regional prosecutor Yuriy Danylchenko told reporters.
Police earlier said they had been in contact with the man via the telephones of the hostages, describing his manner as calm. The man had not made any demands, according to the police.
One of the children released by the hostage taker told local media that the man had put explosives into two bottles and threatened to blow himself up if police did not listen to him.
According to the child, the man also claimed he had brain cancer.
The police had said earlier that the man was concerned about last week’s prisoner swap between the Ukrainian authorities and Russia-backed separatists and thought more prisoners should have been released.
In the December 27 swap, Ukraine handed 233 captives over to the Russia-backed separatists in the eastern Ukrainian regions of Luhansk and Donetsk, while the separatists handed 74 Ukrainian nationals over to Kyiv.
The Russia-backed separatists seized parts of the Donetsk and Luhansk regions in March 2014, igniting a conflict that has killed more than 10,300 people.
Hostilities are still ongoing despite a 2015 cease-fire deal, severely straining Moscow's relations with Kyiv and the West.